Or HaChaim on Deuteronomy 6:25/אור החיים על דברים ו׳:כ״ה

1 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."

2I believe that we must understand our verse by remembering that there are two levels of serving G'd. One may serve the Lord out of fear or one may serve the Lord out of love. Every single creature, human or otherwise, is obligated to serve its master out of fear for its survival. Should it fail to do so, Maleachi 1,6 already quotes G'd as asking: "if I am to be served by you because you consider yourselves My slaves and I am your Master, where is the fear of Me?" This is also the meaning of Deut.10,12: "what does the Lord ask of you except to fear Him, etc?" The second level of serving G'd is service out of love for G'd. This is, of course, a great מצוה but it is not a requirement that man must love his Master. Legally speaking it suffices that the slave does not hate his Master. On the other hand, the master is obligated to look after the physical needs of the slave such as food, shelter, medical attention, etc., all in accordance with the master's resources. Moses writes "G'd has commanded us to fear Him," i.e. our obligation is to revere G'd whereas His obligation to us is לטוב לנו ולהחיותינו, "to ensure that we are well off and to keep us alive" in return for our discharging our obligation towards Him.

3Moses added the words כהיום הזה, "as of this day," meaning that just as G'd is discharging His obligation towards us today, so He will continue to do so. Devarim Rabbah 7 describes that while the Israelites were in the desert their garments grew with them as required, the clouds performed ironing duties, etc. Concerning the group of people who served the Lord out of love the Torah writes וצדקה תהיה לנו "this is accounted as a charitable act for us" as we are not obligated to perform service of the Lord from love. The nature of this love is described in Chovot Halevavot chapter אהבת השם section one in these words: "Love of G'd is a longing of one's soul and its inclining towards the Creator; this is a tendency of one's own self to cleave to the supreme Light represented by the Lord our G'd."

4The Torah writes: כאשר צונו "as He commanded us," to describe that the reason we relate to G'd out of love is not because we have any ulterior motives when we serve Him thus. We find the same idea in Psalms 40,9: "to do what pleases You, my G'd, is my desire." This is a description of someone who performs G'd's will out of pure love. Please read what I have written in Leviticus 18,2 on the verse כמעשה ארץ מצרים. In return for this kind of service of the Lord man is entitled to expect some reward even as a right. Although in truth we ought to pay a reward to G'd who has allowed us to taste the sweetness of His love for us, a pleasant sensation beyond compare, such people deserve the reward for the period they strove to perfect themselves before they came to the realisation that actually they owe G'd and not vice versa.

5Another allusion contained in our verse is based on Tikkuney HaZohar 21 that by observing the commandments we will secure our share in His שכינה, also known as צדקה.