Do not offer the blood of a sacrifice to Me along with anything leavened, and do not let any of the sacrifice from the Passover Feast remain until morning.
Here is a repetition of several appointments made before, especially relating to their solemn feasts. When they had made the calf, they proclaimed a feast in honour of it; now, that they might never do so again, they are here charged with the observance of the feasts which God had instituted.
Commenting on Exodus 34:18-27
And he was there with the Lord forty days and forty nights,.... These were other forty days and nights, besides those he had been with the Lord, when he came down and broke the two tables in his hand, on sight of the idolatry of the people; yea, not only the Jewish writers think that he was on the mount three times forty days and...
The blood of my sacrifice - That is, the paschal lamb. See Clarke on Exo 23:18 (note).