“His master saw that the Lord was with him, and everything that he did, the Lord made his undertaking successful” (Genesis 39:3). The Rabbis say: “His master saw that the Lord was with him” – but ultimately, he forgot, as it is written: “God has caused me to forget all my toil” (Genesis 41:51).20“The Lord was with him” in that Joseph would review his Torah studies, but ultimately, over time, he forgot them (Etz Yosef).
Rav Huna said in the name of Rav Aḥa: He would whisper and enter and whisper and exit.21He was constantly whispering his studies, or praying (see Yefeh To’ar). [Potiphar] would say to him: ‘Pour me boiling water,’ and it would be boiling; lukewarm [water], and it would be lukewarm.22“The Lord was with him” and granted Joseph success beyond the natural order of the world. He said: ‘What, Joseph, are you bringing straw to Efrayim, earthenware pots to Kefar Ḥanina, fleeces to Damascus, sorcery to Egypt – sorcery in a place of sorcerers?’
Until when? Rabbi Ḥiyya said: Until he saw the Divine Presence standing over him. That is what is written: “His master saw that the Lord was with him.”