This is from Chapter Seven of the Ksitigarbha Sutra:
無常大鬼不期而到。

Variously translated as
“The great ghost of impermanence can come to one at any time.”
https://foguangpedia.org/ksitigarbha-sutra/

“Time is transient, and death will come to one at any moment.”
http://www.buddhanet.net/pdf_file/ksitigarbha.pdf

“The demon Avidya [Death] often arrives unexpectedly.”
http://www.buddhism.org/Sutras/2/ksitigarbha_sutra.htm

“After death the Great Ghost of Impermanence will take the spirit of the deceased away without warning.”
https://ksitigarbhasutra.com/

無 mu (무); to be without, no, not, nothing
常 sang (상); always, constant, forever, invariable
大 dae (대); great
鬼 gwi (귀); ghost, spirit
不 bul (불); not
期 gi (기); period of time
不期 = unexpected
而 i (이); and
到 do (도); arrive