Numbers 15:25

They have brought their offering as a fire-offering to Adonoy. This refers to that which is stated in our parshah, namely the ox as the olah-offering, as it is said, “a fire-offering to Adonoy.”

And their sin-offering. This refers to the goat.

and let the priest make atonement for all the congregation of the sons of Israel, and it shall be forgiven them; for it was an error, and they have brought their oblation, an offering before the Lord, even an offering for their sin have they presented before the Lord for their error;

AND THEY HAVE BROUGHT THEIR OFFERING, AN OFFERING MADE BY FIRE UNTO THE ETERNAL. This refers to the bullock as a burnt-offering mentioned [in the preceding verse]. AND THEIR SIN-OFFERING, which refers to the he-goat for a sin-offering [mentioned there]. Scripture states this on account of the greatness of the sin, involving as it does all the commandments of G-d, and is thereby saying that although the sin was exceedingly grave, since it was in error and they have brought their offerings for it, the burnt-offering and the sin-offering, they are worthy of atonement. And in the Sifre 111. the Rabbis interpreted this verse on the basis of its [apparent] redundancy: “Rabbi Yashiyah says: If the whole of one tribe [unwittingly] acted [committed idolatry] on the basis of a [mistaken] decision of the [chief] court of that tribe, and the other tribes did so [too, on their word], whence do we know that they [the other tribes] must also bring [these prescribed offerings] on account of them [i.e., the people of the particular tribe who acted according to the decision of its chief court]? Scripture therefore states, ‘and they’ have brought their offering, an offering made by fire unto the Eternal. Rabbi Yonathan says etc.”).
And by way of the Truth, [the mystic teachings of the Cabala], I have already informed you that wherever the Tetragrammaton is mentioned it refers to the attribute of mercy, and the expression ‘liphnei Hashem’ [before the Eternal — as here in the phrase: and their sin-offering ‘before the Eternal’] is like ‘al panai’ (before Me),, 20:3. Literally “upon My face.” and this is similar to what the Rabbis of blessed memory have said: “He and His Celestial Court.” Thus the verse is stating that “they have brought their offering to the Proper Name of G-d [i.e., the Tetragrammaton], (an offering made by fire to the Eternal) where the Hebrew for the Eternal is the Tetragrammaton. Ramban explained at the beginning of his commentary on this verse that their offering refers to the burnt-offering, which was thus offered to the Tetragrammaton, the Divine Name symbolizing G-d’s attribute of mercy; and the second half of the verse speaks of sin-offering brought l’phanai, i.e., to the Name symbolizing the attribute of judgment. Hence [in the concluding words of Ramban] “the sin is atoned for in the attribute of mercy and in the attribute of judgment.” and their sin-offering ‘l’phanai’ (before Me),” and thus the sin is atoned for in the attribute of mercy and in the attribute of judgment. He mentioned this in the case of idolatry [due to the gravity of the sin, because of which they need to be forgiven in both attributes], but in Seder Vayikra where [the sin-offering for violation of] the other commandments is commanded, He mentioned many times ‘liphnei Hashem’ (before the Eternal). and the reason for this is clear.