The passuk states, “הנסתרות לה’ אלהינו והנגלות לנו ולבנינו עד עולם, that which is hidden is to Hashem our G-d, and that which is revealed is to us and our children forever.” What are the נסתרות, hidden things, which are to Hashem, and what are the נגלות, revealed things, that are to us and our children? Rashi explains the revealed things refer to sins which are seen and noticed by people. We must remove the bad from our midst, and if we don’t get rid of the bad, Hashem will punish us. Each Yid is a cosigner for another Yid and is responsible for him. The hidden things refer to sins which people do secretly, without anyone else knowing, such as a sin which is transgressed with one’s thought. A person does not know another person’s thoughts and is unable to be aware that he sinned. The Ramban specifies, if one does idolatry in hiding where no one sees; although we are unaware and can’t do anything about it, Hashem knows and will punish him.
Onkelos translates הנסתרות לה’ אלהינו as “that which is hidden, is before Hashem our G-d.” The Ramban explains, this refers to sins that are hidden from the person who transgressed them, the person himself is unaware that he sinned. This is as it states, “שגיאות מי יבין מנסתרות נקני, who knows about accidental sins, clean me from the hidden sins.” These are sins which are not known to those who did them, however they are known to Hashem. For the sins which are נגלות, known, the intentional sins, one will be punished with the curse stated in these pessukim. However, for the נסתרות, the hidden sins, which one is not aware that he transgressed, it will not be included in the curse mentioned in this parsha.
On Yom Kippur we confess our sins and we repent with the al chaits. At the end of the al chaits we say, “The aveiros which we know about and the aveiros which we do not know about. For those which we know about we already confessed and asked for forgiveness, and for those which we do not know about, before You they are revealed and known as it states, “הנסתרות לה’ אלהינו.” Similarly, in selichos we also mention, “Hashem knows about everything, even the sins which we did not notice ourselves.” We see, not only are we responsible for sins that we do which we are aware of, but we are also responsible for sins that we do which we are unaware of. On Rosh Hashanah we mention in zichronos; Hashem remembers everything, from the beginning of creation, all that already happened, and even things which we do not realize that happened, by sinning without knowing. Hashem knows and remembers all that happens, and a person is responsible for every action, no matter what.
Rashi explains: if for a sin without awareness one is responsible, then for doing something good without awareness one certainly will receive credit. This is as it states, “When you are harvesting in your field and you will forget omer in the field, do not return to take it; it shall be for the convert, the orphan, and widow, in order that you will be blessed.” Rebi Eliezer ben Azaria says the passuk gives bracha to one who did a mitzva without knowing. From here it is derived that if one had a coin tied in his garment which fell out, and a poor person found it and is supported from it, Hashem will give him bracha. Hashem is aware of every act that is done, whether known to us or not, and He will compensate accordingly.
Let us be careful with all our actions, as Hashem knows and remembers everything we do, and compensates accordingly!