(Devarim 11:22) "… that I command you to do": Why is this written? Because it is written (Ibid. 28:1) "And it shall be if you shall hear, etc." I might think that if one hears words of Torah, he may sit and do nothing; it is, therefore, written (Ibid. 11:22) "you shall keep … to do it" — you shall revert to doing it. If one learned Torah, he has one mitzvah. If he learned and kept, he has two. If he learned and kept and did, there is nothing higher than this.
(Ibid.). "to love the L-rd your G-d": Lest you say: I will learn in order to sit in sessions; so that I merit eternal life in the world to come; it is, therefore, written "to love the L-rd your G-d" — Learn in any event; honor will come as a matter of course. And thus is it written (Proverbs 4:12) "For they (words of Torah) are life to those who find them, and to all his flesh, healing," and (Ibid. 3:18) "It (Torah) is a tree of life to those who hold fast to it, and happy are those who uphold it," and (Ibid. 4:9) "It will give your head an ornament of grace": in this world; "a crown of glory will it accord you": in the world to come. R. Eliezer b. R. Tzaddok says: "Do things (mitzvoth) for the sake of doing them, and speak of them for their own sakes." And thus does Hillel say: "One who makes use of the 'Crown' (for his own purposes) passes away" (from the world.) And thus was he wont to say: "Now if Belshazzar, who made use of the Temple vessels, which were chol (i.e., mundane), was uprooted from this world and the world to come, how much more so, one who makes use of (i.e., exploits) the vessel (Torah) with which this world and the world to come were created!"