אלשיך
Alshekh on Torah, Deuteronomy 24:19
Q — The verse seems to say that you should leave the forgotten sheaves for the poor 'so that Hashem will bless you' — which sounds uncomfortably like avodah on condition of reward. Is leaving the sheaves transactional?
A — The 'למען יברכך' isn't a payoff for the kindness; it's a corrective to a different misconception. A person might assume that mitzvot to help the ger, yatom, and almanah exist *for their sake* — to feed them. The Torah pushes back: 'לא יחסר לי לפרנסם בלעדיך' — Hashem can feed them without you. The mitzvah of shichcha is the proof: a sheaf you didn't even know about ended up benefiting them; Hashem could have arranged that without your involvement. So why is there a mitzvah at all? 'אך בזה חפצתי למען זכות אותך' — the mitzvah exists for *your* benefit, to give you the zechut. The 'למען יברכך' is then not a transaction but a correction: the mitzvah is not about them, it's about you. The blessing is built into the structure, not bartered for.
הלא תראה כל מה שאני מצוך על גר יתום ואלמנה אל יעלה על רוחך כי לתועלתם אני מצוה עליך שתרחם עליהם, כי אינך בזה אלא טועה כי הלא לא יחסר לי לפרנסם בלעדיך. אך בזה חפצתי למען זכות אותך שאברכך בזכות מצוה זו שתעשה.