This is the short version from the Gateless Gate

https://cbetaonline.dila.edu.tw/zh/T2005_001

百丈野狐

百丈和尚。凡參次有一老人。常隨眾聽法。眾人退老人亦退。忽一日不退。師遂問。面前立者復是何人。老人云。諾某甲非人也。於過去迦葉佛時。曾住此山。因學人問。大修行底人還落因果。也無。某甲對云。不落因果。五百生墮野狐身。今請和尚。代一轉語貴。脫野狐遂問。大修行底人還落因果。也無。師云。不昧因果。老人於言下大悟。作禮云。某甲已脫野狐身。住在山後。敢告和尚。乞依亡僧事例。師令[A2]維那白槌告眾。食後送亡僧。大眾言議。一眾皆安涅槃堂。又無人病。何故如是。食後只見師領眾。至山後巖下。以杖挑出一死野狐。乃依火葬。師至晚上堂。舉前因緣。黃蘗便問。古人錯祇對一轉語。墮五百生野狐身。轉轉不錯。合作箇甚麼。師云。近前來與伊道。黃蘗遂近前。與師一掌。師拍手笑云。將謂。胡鬚赤更有赤鬚胡。

無門曰。不落因果。為甚墮野狐。不昧因果。為甚脫野狐。若向者裏著得一隻眼。便知得。前百丈贏得。風流五百生。

頌曰。

不落不昧 兩采一賽 不昧不落
千錯萬錯

代一轉語貴 please give me one precious turning word
代 ?? (replace, take the place of, to act for, on behalf of)
一 one
轉 revolve, turn
語 word
貴 precious

One of the main reasons I wanted to track this down is to take a closer look at the question that is at heart of this story: 大修行底人還落因果. “Does a person of great accomplishment return to falling into cause and effect?” What is a “大修行底人”, and what does it mean to “還落因果”?

AND what the heck does 黃蘗便問。古人錯祇對一轉語。墮五百生野狐身。轉轉不錯。合作箇甚麼。mean?

黃蘗便問 Huangbo asked
。
古人 old man
錯祇 mistake
對一轉語 ???
。
墮 fall
五百生 500 lifetimes
野狐身 wild fox body
。
轉轉 revovle revolve (how might things have turned out?)
不錯 not made a mistake?
。

AND, what the heck does “胡鬚赤. 更有赤鬚胡” mean?
胡 barbarian
鬚 beard
赤 red
.
更 change, replace, take turns
有 exist, there is
赤 red
鬚 beard
胡 barbarian