תּלמוד אויף בראשית 41:46

Sixty-three, and fourteen more till Joseph was born make seventy-seven, and it is written, “And Joseph was thirty years old when he stood before Pharaoh” (Genesis 41:46). This makes a hundred and seven. Add seven years of plenty and two of famine, and we have a hundred and sixteen, and it is written, “And Pharaoh said to Jacob, How many are the days of the years of your life?

R. Levi said : A man should always wait up to twenty-two years for [the fulfilment of] a good dream. Whence is this learnt ? From Joseph ; for it is written, "These are the generations of Jacob. Joseph, being seventeen years old" etc. (ibid. v. 2), and it is written, "And Joseph was thirty years old when he stood before Pharaoh" (ibid. xli. 46). From seventeen to thirty — how many years is it? Thirteen ; add the seven years of plenty and two of famine, hence we get twenty-two.