עקידת יצחק
Akeidat Yitzchak 70:1
Q — Why are the rewards for mitzvos framed as material — rain, harvest, peace — and not spiritual? Why so elaborate a list of blessings and curses? Is bodily plenty really the Torah's promised reward?
A — The physical blessings and curses are not the reward itself but the conditions and the removal of impediments, so that a person can serve God in completeness. Want, war, and illness distract and disable avodah; plenty and peace clear the way for it. The Torah details the material outcomes because they are the arena in which spiritual life is either freed or obstructed — the true שכר is the unhindered service of God that abundance makes possible, and the curses are the obstacles that estrangement brings.
יבאר למה יעדה התורה השכר הגשמי. וירבה מחלוקת על זה הפילוסוף ובעלי הדתות ועם בעלי התורה האלקית: במדרש (ויקרא רבה פרשה ל"ה) מאי דכתיב (תהלים קי"ט) חשבתי דרכי ואשיבה רגלי אל עדותיך.