Shemos 27:20

וְאַתָּ֞ה תְּצַוֶּ֣ה ׀ אֶת־בְּנֵ֣י יִשְׂרָאֵ֗ל וְיִקְח֨וּ אֵלֶ֜יךָ שֶׁ֣מֶן זַ֥יִת זָ֛ךְ כָּתִ֖ית לַמָּא֑וֹר לְהַעֲלֹ֥ת נֵ֖ר תָּמִֽיד

“And you shall command…” .

In the Midrash (Shemos Rabbah 36:1): “A leafy olive tree, fair with goodly fruit” (Yirmeyahu 11:16). This is as it is written (Tehillim 48:3): “Beautiful in elevation, the joy of the whole earth.” For when a person would enter the Holy Temple full of sins, and would offer a sacrifice and be forgiven, there was no joy greater than that.

Now, there is a difficulty raised by the Bikkurei Aviv (Tetzaveh) : We know that a sacrifice only helps for an inadvertent sin, not for a willful one. How, then, could a person full of sins (implying willful ones) find atonement through a sacrifice?

This can be settled according to the words of the Maharam Alshich (Vayikra 4:2, 27 and elsewhere): There is no “inadvertent sin” that wasn’t preceded by a “willful sin”—meaning, because the person did not set his heart to repent for previous minor willful negligence, God allows him to stumble into an inadvertent sin. This is done specifically so that he will be moved to repent.

From this, it is understood that if a person repents for the original willful sin and then brings a sacrifice for the inadvertent sin that occurred recently, the Holy One, Blessed be He, forgives him for both. This is because the entire purpose of the inadvertent sin was to bring him to this moment of repentance. Consequently, he is atoned for all his sins.