אור החיים — ולפני יוסף יֻלד שני בנים בטרם תבוא שנת הרעב

Q — The Gemara (Taanit 11a) derives from 'ולפני יוסף יֻלד שני בנים בטרם תבוא שנת הרעב' that one may not have marital relations during years of famine — Yosef's sons were born before the famine, not during. But Tosafot object: Yocheved was born 'between the walls' as Yaakov's family entered Egypt, during the famine years, so the family evidently did have relations then.

A — Or HaChaim engages the apparent contradiction between the derived prohibition and the case of Yocheved. The resolution draws on the Gemara's own qualification — 'חסוכי בנים,' those who have not yet fulfilled פריה ורביה, are permitted relations even in famine years — together with the chronology of Yocheved's conception, so that the families involved fell within the permitted category rather than violating the rule learned from Yosef.