Rabbi Ḥiyya bar Abba taught in the name of Rabbi Joḥanan that when in Pharaoh conferred power on Joseph, Pharaoh's astrologers questioned whether Pharaoh would set in power over them a slave whom his master bought for 20 pieces of silver. Pharaoh replied to them that he discerned royal characteristics in Joseph. Pharaoh's astrologers said to Pharaoh that in that case, Joseph must be able to speak the 70 languages of the world. That night, the angel Gabriel came to teach Joseph the 70 languages, but Joseph could not learn them. Thereupon Gabriel added a letter from God's Name to Joseph's name, and Joseph was able to learn the languages, as reports, "He appointed it in Joseph for a testimony, when he went out over the land of Egypt, where I (Joseph) heard a language that I knew not." The next day, in whatever language Pharaoh spoke to Joseph, Joseph was able to reply to Pharaoh. But when Joseph spoke to Pharaoh in Hebrew, Pharaoh did not understand what he said. So Pharaoh asked Joseph to teach it to him. Joseph tried to teach Pharaoh Hebrew, but Pharaoh could not learn it. Pharaoh asked Joseph to swear that he would not reveal his failing, and Joseph swore. Later, in , when Joseph related to Pharaoh that Jacob had made Joseph swear to bury him in the Land of Israel, Pharaoh asked Joseph to seek to be released from the oath. But Joseph replied that in that case, he would also ask to be released from his oath to Pharaoh concerning Pharaoh's ignorance of languages. As a consequence, even though it was displeasing to Pharaoh, Pharaoh told Joseph in , "Go up and bury your father, as he made you swear."</ref>