신명기 6:25의 주석

This is what I had in mind when I said to you וצדקה תהיה לו לטוב לנו כל הימים, it will be good for us not only in this life but will be a charitable act assuring us of life in the hereafter.

וצדקה תהיה לנו, "and it will be a righteousness for us, etc." What is the meaning of the word צדקה in this context? Nachmanides explains that the word refers to the reward for מצוה-performance. Inasmuch as we are G'd's slaves we are not entitled to any reward at all. If, nonetheless, G'd grants us a reward for our observing His commandments this is in the nature of צדקה, charity, as we have no claim. I do not believe that this explanation answers our problem. Moreover, we also need to understand the meaning of the words לפני ה׳ כאשר צונו, "before the Lord as He commanded us."

וצדקה תהיה לנו, “and it will be a merit for us, etc.” Although we are duty bound to observe all these commandments, and the idea that we would be entitled to be rewarded for doing so is quite beyond reason, Moses assures the people that such reward will nonetheless be in store for them, this being the nature of Hashem, Who devises ways and means to enable His people to acquire merits. Ibn Ezra writes that some scholars see in our verse (the word צדקה) an allusion to the world to come, where the reward for keeping the commandments will be handed out. According to the plain meaning of the text, the meaning is that it is no more than fair and just that we keep Hashem’s commandments as by what He did at the Exodus He has acquired us as His eternal servants obligated to do His bidding.