“Joseph resided in Egypt, he, and his father's household; Joseph lived one hundred and ten years” (Genesis 50:22). “Joseph resided in Egypt…” – there are six pairs whose years were equal: Rebecca and Kehat, Levi and Amram, Joseph and Joshua, Samuel and Solomon, Moses and Hillel the elder, Rabbi Yoḥanan ben Zakkai and Rabbi Akiva. Moses spent forty years in Pharaoh’s palace, forty years in Midyan, and he served Israel for forty years. Rabbi Yoḥanan ben Zakkai engaged in commerce for forty years, studied Torah for forty years, and served Israel for forty years. Rabbi Akiva was an ignoramus for forty years, studied Torah for forty years, and served Israel for forty years.