Comparing the very different lives of two righteous individuals teaches us that there are certain matters that are not dependent on a person’s deeds, but on his astrology.

Rava said: Concerning length of life and health, children, and sustenance, the matter is not dependent on merit but on astrology. For Rabba and Rav Hisda were both righteous Sages, as this Sage [Rabba] would pray during a drought and rain would fall, and that Sage [Rav Hisda] would pray during a drought and rain would fall.

Nevertheless, Rav Hisda lived ninety-two years, and Rabba lived forty years. In the household of Rav Hisda there were sixty weddings; in the household of Rabba there were sixty bereavements. In the household of Rav Hisda they baked bread from the finest flour even for the dogs, and it was not lacking [as there was so much food]. In the household of Rabba, they had coarse barley bread even for the people, and even that was hard to find. (Shabbat 156a; Moed Katan 28a)