According to “A History of Chinese Buddhist Faith and Life” by Kai Sheng: “we can deduce that Xuanzang translated the text of these gāthās based on the shuo guan Mile pusa shangsheng doushuaitian jing 佛說觀彌勒菩薩上生兜率天經 (Sūtra of Contemplation of Maitreya’s Ascent to Tuṣita Heaven, T 452; hereafter, Shangsheng jing 上生經).”

The translation given in the above work is, in my very inexpert opinion, a little rough around the edges in some places. The paraphrases provided below are very tentative, and rely heavily on the translation in Kai Sheng, et al.

讚彌勒四禮文 (玄奘法師依經翻出)

1.
至心歸命禮，當來彌勒佛。
諸佛同證無為體，真如理實本無緣，為誘諸天現兜率，其猶幻土出眾形。
元無人馬迷將有，達者知幻未曾然，佛身本淨皆如是，愚夫不了謂同凡！
知佛無來見真佛，於茲必得永長歡。故我頂禮彌勒佛，唯願慈尊度有情，
願共諸眾生，上生兜率天，奉見彌勒佛。

至心歸命禮，
sincere mind return/submit life/fate ritual/gift
tentative paraphrase: With sincere mind I bow down and pay homage to

當來彌勒佛。
當來 = future
彌勒佛 = Maitreya Buddha
tentative paraphrase: The Future Buddha Maitreya

諸佛同證無為體，
諸佛 = all Buddhas
同 = together, same
證 = prove, testify, verify
無為 = wúwéi
體 = essence (tǐ, as in 體用, tǐ yòng, “essence function”)
tentative paraphrase: All Buddhas together manifest the unconditioned essence

Hmmm. That 無為 (wúwéi) sent me down a bit a rabbit hole. I ended up at this passage from the Uttaratantraśāstra, aka Ratnagotravibhāga, verse 1.6
非初非中後自性無為體
非初非中 = without beginning without middle
自性 = svabhāva = true nature, buddha nature
無為 = wúwéi
體 = essence (tǐ, as in 體用, tǐ yòng, “essence function”)
及法體寂靜故自然應知
及 = as well as
法 = dharma
體 = essence
寂靜 = silence
故 = cause, reason
自然 = nature (the physical, “natural” world)
應 = should
知 = know

Here’s a translation by Obermiller (1931)
Having by nature no beginning, Middle, nor end, (the Buddha) is immutable.
Being, in his Cosmical Essence, quiescent, He is spoken of as acting without effort.

And now back to our regularly scheduled program (Xuanzang’s Homage to Maitreya) …..

真如理實本無緣，
真如 = tathātā = “suchness”
理 = lǐ = “principle”
實 = true
本 = root
無緣 = without cause
paraphrase: The tathātā principle, the true root of reality, is without cause

為誘諸天現兜率，
為 = for the sake of
誘 = persuade
諸天 = the Gods
現 = reveal
兜率 = Tuṣita
paraphrase: in order to persuade the Gods to reveal Tuṣita

其猶幻土出眾形。
其 = his, her, its; he, she, it, they; that, those
猶 = to be like
幻 = mystical, mysterious, illusion, fantasy
[如夢幻泡影 = like dream illusion bubble shadow, from Diamond Sutra]
土出 = unearth (literally “earth come-out”)
眾形 = all forms
paraphrase: they (the Gods?) are like mysteries that are unearthed in a variety of forms (???)

元無人馬迷將有，
元 = originally
無 = no
人 = person/people
馬 = horse/horses
迷 = lost, confused, bewildered
將 = to take in hand; support; protect; take hold of; use; employ; apply
有 = to have; to exist
paraphrase: originally, humans and animals do not exist, but only appear to exist due to confusion

達者知幻未曾然，
達者 = master
知 = know
幻 = illusion
未曾 = never
然 = so, thus
paraphrase: the master who understands this illusion knows that things were never as they appear to the deluded

佛身本淨皆如是，
佛身 = Buddha body
本淨 = intrinsically pure
皆 = all
如是 = like this
paraphrase: the intrinsically pure body of the Buddha is also like this

愚夫不了謂同凡！
愚夫 = foolish person
不了 = not understand
謂 = say; tell; name; call; regard something as; meaning of
同 = same
凡 = ordinary; common
paraphrase: foolish people do not understand and mistake their misperception for reality

知佛無來見真佛，
知 = know
佛 = Buddha
無 = no
來 = come, arrive
見 = see
真 = true
佛 = Buddha
paraphrase: if you understand that the Buddha does not come from somewhere else, then you see the True Buddha

於茲必得永長歡。
於茲 = here
必得 = must have to
永長 = forever, perpetual
歡 = happy, pleased, glad, joyous
paraphrase: here is where true, perpetual happiness is found

故我頂禮彌勒佛，
故我 = therefore
頂禮 = bow down
彌勒佛 = Maitreya Buddha
paraphrase: therefore I prostrate to Maitreya Buddha

唯願慈尊度有情，
唯願 = only wish
慈尊 = Maitreya
度 = save, liberate (see Four Great Vows)
有 = have
情 = emotion, feeling, love, affection
paraphrase: my only wish is for Maitreya, out of great compassion, will save all sentient beings

願共諸眾生，
願 = wish
共諸 = universal
眾生 = sentient beings
paraphrase: I wish that all sentient beings

上生兜率天，
上生 = above born
兜率天 = Tuṣita Heaven
paraphrase: will be born above in Tuṣita Heaven

奉見彌勒佛。
奉 = serve
見 = see
彌勒佛 = Maitreya Buddha
paraphrase:
and serve and see Maitreya Buddha

——————————

2.
至心歸命禮，當來彌勒佛。
佛有難思自在力，能以多剎內塵中，況今現處兜率殿，師子床上結跏坐。
身如檀金更無比，相好寶色曜光輝，神通菩薩皆無量，助佛揚化救含靈。
眾生但能至心禮，無始罪業定不生。故我頂禮彌勒佛，唯願慈尊度有情，
願共諸眾生，上生兜率天，奉見彌勒佛。

repeated: With sincere mind I bow down and pay homage to the future Buddha Maitreya

佛有難思自在力
佛 = Buddha
有 = have
難思 = inconceivable (lit: difficult think)
自在力 = freedom (lit: oneself life strength)
paraphrase: The Buddha has inconceivable freedom

能以多剎內塵中
能以 = antidotes (dharmic), or: able to
多 = many
剎 = kṣetra
內塵 = sixth guṇa, mental objects, inner dust
中 = midst
paraphrase: He acts freely throughout the many kṣetras and even in the midst of the inner dust

況今現處兜率殿
況 = let alone, even more so
今 = present
現 = appear, appearance
處 = reside, live, dwell
兜率 = Tuṣita
殿 = palace
paraphrase: And even more so does he appear freely and reside in the Tuṣita Palace

師子床上結跏坐
師子 = lion, also fearless teacher, great master, lion-like master
床 = bed, raised platform
師子床 = Lion Throne, the high seat for a great teacher
上 = above
結 = knot, tie, bind, connect
跏坐 = sit in lotus position
paraphrase: Above, on his Lion Throne, sitting in the Lotus position

身如檀金更無比
身 = body
如 = like, as if
檀金 = some kind of special gold??
更 = change
無比 = no comparison
paraphrase: his body like refined gold beyond comparison

相好寶色曜光輝
相好 = major and minor marks of a Buddha
寶色 = form world
曜 = glorious
光輝 = brilliance
paraphrase: with the major and minor marks of a Buddha his glorious brilliance shines throughout the form world

神通菩薩皆無量
神通 = Abhijñā (see fourth ox picture, “Getting Hold of the Ox”)
菩薩 = Bodhisattva
皆 = all
無量 = beyond counting
paraphrase: The Bodhisattvas possessing abhijñā are also beyond counting

助佛揚化救含靈
助 = help
佛 = Buddha
揚 = spread, flow, flutter, raise, lift, hoist
化 = change, transform, dissolve, die
救 = aid, support, save, rescue
含靈 = sentient beings (hold spirit)
paraphrase: and they help the Buddhas to propagate (the Dharma) and rescue sentient beings

眾生但能至心禮
眾生 = sentient beings (everything born)
但 = only, just
能 = able to, capable of
至心 = sincere mind
禮 = lǐ = ritual/gift
paraphrase: if sentient beings are only capable of performing this ritual with sincerity

無始罪業定不生
無始 = without beginning
罪業 = criminal karma
定 = stable, fixed, samadhi
不生 = unborn/non-birth
paraphrase: deeply rooted evil karma without end will be cut off

故我頂禮彌勒佛
therefore bow down Maitreya Buddha, etc

——————————

3.
慈尊寶冠多化佛, 其量超過數百千, 此土他方菩薩會, 廣現神變寶窗中.
佛身白毫光八萬, 常說不退法輪因, 眾生但能修福業, 屈伸臂頃值慈尊.
河沙諸佛由斯現, 況我本師釋迦文, 故我頂禮彌勒佛, 唯願慈尊度有情，
願共諸眾生，上生兜率天，奉見彌勒佛。

至心歸命禮當來彌勒佛

其量超過數百千
其 = his, her, its, their
量超 = excess
過數 = excessive
百千 = hundred thousand
paraphrase: vast, extensive incalculably many

此土他方菩薩會
此土 = sahāloka = saha world = saṃsāra = “this world”
他方 = “the other world”
菩薩 = Bodhisattva
會 = meet, match, marry, assembly
paraphrase: Bodhisattvas assemble in this world and the other world

廣現神變寶窗中
廣現神變 = This appears to be a quote from a biography of Nagarjuna. I found one translation (here): “extensively displaying spiritual transformations”.
Also check this shit out: http://www.drbachinese.org/online_reading/sf_others/pat01/contents.htm
寶 = treasure
窗 = window, portal
中 = middle, midst
paraphrase: extensively displaying their spiritual powers in the midst of the treasure window

佛身白毫光八萬
佛身 = Buddha body
白毫 = ūrṇā = circle of hair where the Buddha’s third eye is, one of the “major marks” of a Buddha (the 31st to be exact)
光 = light
八萬 = eight myriads, 8,000
paraphrase: And 8000 rays of light blaze out from the ūrṇā of the nirmanakaya

常說不退法輪因
常說 = always say
不退 = no retreat
法輪 = dharmacakra = wheel of the Dharma
因 = to follow (a tradition or teaching)
paraphrase: He always turns the wheel of the Dharma and never turns back.

眾生但能修福業
眾生 = sentient beings (everything born)
但 = only, just
能 = able to, capable of
修福 – cultivate virtue
業 = karma
paraphrase: if sentient beings can only cultivate virtuous karma

屈伸臂頃值慈尊
屈伸臂頃值慈尊
屈伸臂 = bow (bend extend arm)
頃 = qǐng = moment; lean toward
值 = zhí = encounter
慈尊 = maitreya
paraphrase: in the moment of prostrating they will meet Maitreya

河沙諸佛由斯現
河沙諸 = gaṃgānadī vālukā = Ganges sands (lit: river sand all)
佛 = Buddha(s)
由 = cause, reason
斯 = this, these
現 = appear, manifest
paraphrase: and also as many Buddhas as the grains of sand in the Ganges

況我本師釋迦文
況 = let alone, how much more so
我 = my, our
本師 = root teacher
釋迦文 = Shakyamuni
paraphrase: even more so my root teacher Shakyamuni

故我頂禮彌勒佛, 唯願慈尊度有情，
願共諸眾生，上生兜率天，奉見彌勒佛。
therefore bow down Maitreya Buddha, etc ….

——————————

4.
諸佛常居清凈剎, 受用報體量無窮, 凡夫肉眼未曾識, 為現千尺壹金軀.
眾生視之無厭足, 令知業果現閻浮, 但能聽經勤誦法, 逍遙定往兜率宮.
三途於茲必永絕, 將來同證一法身, 故我頂禮彌勒佛, 唯願慈尊度有情，
願共諸眾生，上生兜率天，奉見彌勒佛。

諸佛常居清凈剎
諸佛 = all Buddhas
常居 = always dwell
清凈 = completely pure
剎 = kṣetra
paraphrase: All Buddhas always dwell in completely pure kṣetras

受用報體量無窮
受 = receive
用 = use, employ, make use of
受用 = when combined these two characters denote benefit, profit, enjoyment
報 = karmic rewards and/or punishments; sometimes translated as “retribution” but can also be translated as “reward”
體量 = volume, area
無窮 = infinite
paraphrase: Enjoying their karmic rewards throughout infinite space

凡夫肉眼未曾識
凡夫 = common people
肉眼 = māṃsacakṣus (skt) = naked eye
未曾 = never
識 = vijñāna = consciousness
paraphrase: Although this is unseen and unknown to ordinary beings

為現千尺壹金軀
為 = do, make, for, on behalf of
現 = appear, manifest
千尺 = one thousand feet
壹 = one (banker’s anti-fraud numeral)
金 = gold
軀 = body
paraphrase: Nevertheless, their thousand foot tall golden body is right here

眾生視之無厭足
眾生 = sentient beings
視 = see, look at
之 = it
無厭足 = insatiable, never get enough, not satisfied
paraphrase: Living beings who see it cannot reject it

令知業果現閻浮
令知 = to know
業果 = karma fruit
現 = appear
閻浮 = Jambudvīpa
paraphrase: And now they know how karmic fruits appear in Jambudvīpa

但能聽經勤誦法
但能 = only able to
聽 = hear
經 = sutra
勤 = diligent
誦 = recite, read aloud
法 = Dharma
paraphrase: If only sentient beings hear this Sutra and diligently recite this Dharma

逍遙定往兜率宮
逍遙 = to walk freely, to be happy without care
定 = stable, steady, fixed, samadhi
往 = to go, to head for, to, towards
兜率宮 = Tuṣita Palace
paraphrase: They will easily and steadily go toward the Tuṣita Palace

三途於茲必永絕
三 = three
途 = way, path, method
於 = with, on, at
茲 = this, present
必 = surely, most certainly
永 = perpetual, eternal
絕 = exhaust, sever, break off, terminate
paraphrase: And the three lower realms are most certainly forever cut off

將來同證一法身
將來同證一法身
將 = to take in hand; support; protect; take hold of; use; employ; apply
來同 = come together
證 = prove, testify, verify
一法身 = singular Dharma Body
paraphrase: And they will attain the Single Dharma Body

故我頂禮彌勒佛, 唯願慈尊度有情，
願共諸眾生，上生兜率天，奉見彌勒佛。
therefore bow down Maitreya Buddha, etc ….