Midrash su Salmi 105:17

What did he tell Jacob? Our rabbis maintain that he told his father: They treat the children of Bilhah and Zilpah as though they were servants. They call them servants, but I act toward them as one does to a brother, as it is said: Even with the sons of Bilhah and with the sons of Zilpah (ibid., v. 2). The Holy One, blessed be He, said to him: Be assured you will be punished with the very word you have spoken, as it is said: And Joseph was sold for a servant (Ps. 105:17).

"Joseph was seventeen years of age, etc" (Genesis 37:2), and it further says "He was a youth" (ibid.), rather that he did youthful things. He touched up his eyes, he picked up his heels, he fixed his hair. "He was a shepherd... he brought negative reports [of his brothers, to his father]" (ibid.). What did he say? Rabbi Meir and Rabbi Yehuda and Rabbi Shimon [offered explanations]. Rabbi Meir said, [he said to his father Ya'akov] "Your sons are suspect regarding [the consumption of] a limb of a living animal". Rabbi Shimon said "They cast their eyes on the daughters of the land". Rabbi Yehuda said "They scorn the sons of the maidservants and call them slaves". Rabbi Yehuda son of Simon said, on his words [??] he was struck -- "honest scales and balances are the LORD's" (Proverbs 16:11). The Holy Blessed One said to him, "You said "Your sons are suspect regarding a limb of a living animal" -- by your life, even in a time of corruption they never did anything but slaughtered and [then] ate, (Genesis 37:31) "They slaughtered a kid"! You said they scorned the sons of the maidservants and called them slaves -- (Psalms 105:17) "Yosef, sold into slavery". You said they cast their eyes on the daughters of the land -- by your life, that I will stimulate in you the bear [??], (Genesis 39:7) "And his master's wife cast [her eyes upon Yosef]".