English: Rabbi Yehoshua ben Korchah said: When a person approaches the age of his parents he should fear five years before and five years after. Yitzchak was 123; he said, Perhaps I am near the age of my mother, who died at 127—I am within five years of her span—therefore he worried.
On the daf / in context: Yitzchak’s uncertainty about the day of death is linked to the ages of his parents; at 123 he fears Sarah’s span of 127.
Type of Learning
Derash on the verse (Rashi / midrash) — not a formal named middah of the 13: the fear of death is timed by the parents’ ages.
What Is Learned
Yitzchak did not know the day of his death; having reached near his mother’s age-span, he feared within five years before and after.