כל העוסק בתורה לשמה זוכה לדברים הרבה (אבות ו:א)

Hashem gave 613 mitzvahs, but we can’t perform all of them since some are designated for Kohanim, some can only be achieved if you live in Eretz Yisroel, and some mitzvahs could only be performed during the times of the Beis Hamikdash. Chazal says there is a way to fulfill all mitzvahs “העוסק בתורת עולה כאילו הקריב עולה” – one who learns the halachas of a Korban Olah is as if he sacrificed the Korban.” Understandably, this is when one learns תורה לשמה – then he is worthy  לדברים הרבה – as if he fulfilled many mitzvahs, which he couldn’t have performed otherwise.