Perhaps, you need to read the Hebrew of Exodus 32:25 - 29.
Abandon all existing doctrine and interpretation. Read it like your friend wrote you an email. Don't care what "experts" have commented. Just read the Hebrew plainly without religious allegiance.
You will notice there is no imperative, no incompletion verb, among the verbs that concern you.
You see, Biblical Hebrew has no past. present, future tenses. Verbs are either stative, or incomplete. Stative means stating the action.
When a verb is inflected as an incomplete form, it could mean either "will", "should", "may", "then", "could". i.e., it could be an instruction, a prediction, a command, a subjunctive, a proposal, a possibility.
But the verbs that concern you in the passage are stative. When verbs are stative, it could mean the actions are already performed, or ongoing.
Also, for a few hundred years, understanding of biblical Hebrew has been screwed up (sorry for the harsh term) by the inversive-vav theory. Like as though ancient shepherding Israelites would really go thro all the trouble to develop a language that would invert the tense due to a preceding sequence-conjunction. Rather than follow every sequentially-tensed language that had developed and spoken by humans - where a sequence-conjunction simply helps to anchor the time reference on the previous phrase.
The proof of the screwedupness of inversive-vav theory is every passage you read, and then compare to the English/Greek translations, the inversive-vav is inconsistently applied. Like having grammar is pointless, and one has to use "common-sense" and arbitrary "context" when to apply the inversive-vav.
In verse 25:
וירא משה
In sequential-tense language, verse 25 would say: "and Moses will/shall see".
Whereas, the silly inversive-vav theory has been willy-nilly chosen to be applied here, by English translations to say, "and Moses saw".
In verse 26:
ויעמד משה ... ויספו
In sequential-speak: And Moses will/shall/would stand ... and they will congregate
Verse 27:
וימר להם כה אמר יי
In sequential-speak: And he will/shall/would say thus says the LORD
There are these initial incompletion verbs, but the verbs that follow them are all stative.
It means that ....
Moses will see the orgy, and Moses will stand at the gate, and the people will congregate, and Moses will say thus the LORD says/said a man placed his sword upon his side, crossed back and forth from gate to gate in the encampment and killed, a man against his brother ....
And the sons of Levi will be doing as Moses had said, and shall fall among the people on that day, about 3000 man.
And Moses will say, they fill(ed) your hand today to the LORD as man in his son, and in his brother, and to give you today blessing.
And it will be from tomorrow Moses will/shall say, to the people, you have sinned a great sin .... Maybe I should make atonement for your sin?
Because these people, had an orgy, killed each other and then even went on to impersonate the blessing of the LORD. And Moses then questions maybe he should go up the mountain again, just to atone for their sins. You take it for granted that I will atone for your sins, huh?
If you translated the Hebrew thro phrase literal translation, to a Papua New Guinea language, in sequential-tense language, that person would simply say, the killing has already occurred or is currently taking place. G'd did not command the killing. G'd was simply saying thro/to Moses, "look at the orgy and killing that is happening."
The English translations do not even bother to reflect the sarcasm of Moses.
It is time we flushed the worthless inversive-vav theory away. But we can't because a lot of established doctrines would be thrown with the dirty bath water. Perhaps those established doctrines are the dirty bath water.