Comentario sobre Exodo 32:5

וירא אהרן AND WHEN AARON SAW that there was the breath of life in it — as it is said with reference to the golden calf, (Psalms 106:20) “[They changed their glory] into a similitude of an ox that ate grass” — and he realized that Satan’s work had succeeded and that he had no argument (lit., mouth) to put them (the people) entirely off.

AND AARON SAW. The meaning of this verse is that Aaron saw them set on evil, intent upon making the calf, and he arose and built an altar and proclaimed, Tomorrow shall be a feast to the Eternal,²⁷⁴Verse 5. so that they should bring offerings to the Proper Name of G-d upon the altar which he built to His Name, and that they should not build altars to the shameful thing,²⁹⁸Jeremiah 11:13. and that their intent in the offerings should be [to none] save unto the Eternal only.²⁹⁹Above, 22:19.
It is possible that Aaron said, Tomorrow [shall be a feast], in order to delay them, thinking that perhaps Moses would come in the meantime and they would abandon the calf. But they rose up early in the morning and offered burnt-offerings, and brought peace-offerings.³⁰⁰Verse 6. Now Scripture does not say “and they offered burnt-offerings to it, and brought peace-offerings to it.” The reason for that is that there were some people amongst them who intended them to be for the Name of the Holy One, blessed be He, as Aaron had said, but some of them became corrupted and sacrificed them to the calf. It is with reference to this latter group that the Holy One, blessed be He, said to Moses, they have worshipped it, and have sacrificed unto it,³⁰¹Verse 8. for it is they who were the sinners. And even if it was perhaps Aaron who performed the sacrifical rites, Scripture used an indefinite expression — saying, they offered burnt-offerings and brought peace-offerings³⁰⁰Verse 6. — in order to suggest that Aaron’s intention was directed towards the Name of the Eternal, whilst they set their mind towards the calf which they had made, and thus the owners [of the sacrifices] invalidated them.

חג לה' מחר. So that you will not mix the joy of serving the Lord with any other kind of joy.