וַ֠יִּפְקֹד שַׂ֣ר הַטַּבָּחִ֧ים אֶת־יוֹסֵ֛ף אִתָּ֖ם וַיְשָׁ֣רֶת אֹתָ֑ם וַיִּהְי֥וּ יָמִ֖ים בְּמִשְׁמָֽר׃
And the captain of the guard charged Joseph to be with them, and he ministered unto them; and they continued a season in ward.
Read kabbalistic (mystical) interpretation of Genesis 40:4: and classical mystical sources.