RAV KOOK ON Eikev Part 1: Blessings Over Bread and Torah

Most blessings are of rabbinical origin. There are, however, two exceptions to this rule — blessings that are derived directly from the Torah itself. The first is Birkat Hamazon, recited after meals; the second is the blessing said before learning Torah. The obligation to bless God after eating bread is stated explicitly: “When you eat and are satisfied, you must bless the Lord your God...” (Deut. 8:10). The Sages derived the blessing before studying Torah from the verse, “When I proclaim God’s name [or: when I read God’s teaching], praise our God for His greatness” (Deut. 32:3). These two blessings differ not only in the source for our feelings of gratitude — one is for physical nourishment, the other for spiritual sustenance — but also in when they are said. Why is Birkat Hamazon recited after the meal, while the blessing for Torah study is recited before studying?