John Gill Commentary Genesis 40:21

"And he restored the chief butler unto his butlership again; and he gave the cup into Pharaoh`s hand:" — Genesis 40:21 (ASV)

And he restored the chief butler unto his butlership again , &c.] Put him into the same office he was in before:

and he gave the cup into Pharaoh's hand ; ministered to him in his office the same day, according to his dream and the interpretation of it:

the Targum of Jonathan adds this as a reason of his being restored, ``because he found that he was not in that counsel,'' in which it was consulted to poison Pharaoh, (See Gill on Genesis 40:1).