They continued a season - ימים yamim, literally days; how long we cannot tell. But many suppose the word signifies a complete year; and as Pharaoh called them to an account on his birthday, Genesis 40:20, Calmet supposes they had offended on the preceding birthday, and thus had been one whole year in prison.

And the captain of the guard charged Joseph with them,.... Committed them to his care and custody, he being very probably recommended to him by the keeper of the prison for his prudence and fidelity; and if it was Potiphar, he knew his character full well, and might be now reconciled unto him, as having had a more full and clear account of the affair between him and his wife from the keeper of the prison; and therefore though he might not think fit for his own and his wife's reputation to remove him from prison as yet, nevertheless might be inclined to do him what service he could, as well as honour, as this was, to have two such state prisoners committed to his care. Some render it, "he committed Joseph with them" (x); to be with them, as Jarchi interprets it; they were put together, not merely for the sake of company, but that Joseph might wait upon them, which might be beneficial as well as creditable, as it follows:
and he served them; he ministered unto them, and brought them every thing they wanted:
and they continued a season in ward; or "days" (y); some certain days, many days, a year, as Jarchi and Ben Gersom interpret it, and which is sometimes the use of the word. The story of the butler and baker is told, partly to show the divine faculty of interpreting dreams Joseph was possessed of; and partly to observe the remarkable steps in Providence, though secret, towards his advancement in Pharaoh's court.
(x) "et commisit Josephum cum eis", Junius & Tremellius. (y) "per annum", Pagninus, Vatablus, Schmidt.

The captain of the guard charged Joseph with them--not the keeper, though he was most favorably disposed; but Potiphar himself, who, it would seem, was by this time satisfied of the perfect innocence of the young Hebrew; though, probably, to prevent the exposure of his family, he deemed it prudent to detain him in confinement (see Psalm 37:5).
They continued a season in ward--literally, "days," how long, is uncertain; but as they were called to account on the king's birthday, it has been supposed that their offense had been committed on the preceding anniversary [CALVIN].

The captain of the guard, which was Potiphar, charged Joseph with them - Which intimates that he began now to be reconciled to him.