Why did Isaac marry only at age forty if the Sages teach that eighteen is the age for marriage?

This Torah study examines the question: Why did Isaac marry only at age forty if the Sages teach that eighteen is the age for marriage? The canonical Hebrew discussion develops the issue through the weekly Torah portion and the sources cited there, preserving the distinctions, tensions and practical implications that belong to the source itself. This localized layer is designed for study and discovery; it does not add a new halakhic, medical, legal, historical or empirical ruling beyond the canonical Hebrew source.