When the people saw is literally “And the people saw,” but saw here means “realized” (Durham), or “became aware” (New American Bible). That Moses delayed to come down from the mountain is quite literal, and the verb for delayed has the active form rather than the passive (“was delayed”). This suggests that, in the mind of the people, at least, it was Moses who did the delaying rather than Yahweh. Good News Translation expresses this in an extended clause, “that Moses had not come down from the mountain but was staying there a long time.” The reference to the mountain picks up the narrative from 24.18. In some languages these two clauses will be rendered as “The people saw that Moses had not come down from the mountain but was staying there for a long time, so….”
The people gathered themselves together to Aaron is literally “the people assembled on [or, over] Aaron.” The word for the preposition to may have either a positive meaning (“in front of”) or a negative meaning (“over against”). Good News Translation takes the former, “they gathered around Aaron” (so New Revised Standard Version and others), but New Jewish Publication Society’s Tanakh takes the latter, “the people gathered against Aaron.” It is also possible to take a neutral interpretation and say, for example, “they went to Aaron and said” (Contemporary English Version). It is recommended that translators follow either the positive interpretation above or this more neutral position. And said to him introduces the demand of the people.
Up, make us gods is literally “Rise, you [singular] make for us ʾelohim.” The word for Up often means “Stand up,” but here it is only a call to action. New Revised Standard Version and others have “Come,” but New Jerusalem Bible has “Get to work,” and Durham has “Get busy!” Good News Translation and Contemporary English Version simply omit it. Translators should do what is natural in the receptor language. The word ʾelohim, which is plural in form, may be understood either as gods or as “a god” (Good News Translation and Contemporary English Version). (See the Good News Translation footnote.) Since Aaron made only one gold bull, some translations have the singular, “a god.” (But see verse 4.) Who shall go before us is literally “who [are] they [who] shall go out to our faces.” This, of course, means “to lead us.” The plural verb simply agrees with the plural form of ʾelohim, but the singular meaning may still be intended. This is unusual if only one “god” is intended, but there are other cases where plural forms are used with ʾelohim when the one God is clearly intended. (Gen 20.13 is one example.) Good News Translation places this clause at the end of the verse, “So make us a god to lead us.”
As for this Moses is meant to be disrespectful. Since Moses was still on the mountain, it may be better to say “for that Moses” (New Jerusalem Bible) or “for that man Moses” (New Jewish Publication Society’s Tanakh), combining it with the following phrase. The word “that” also conveys disrespect in English. The man who brought us up out of the land of Egypt is literally “the man who caused us to ascend from the land of Egypt.” This may imply that the people were now at a higher elevation than they were in Egypt. Good News Translation simply has “who led us out of Egypt.” (See the comment on the similar expression at 3.8.) We do not know what has become of him is literally “we do not know what is to him.” This also means “we do not know what has happened to him.” Another way to express the final part of this verse is “That person [or, man] Moses brought us out of Egypt, but nobody knows what has happened to him.”
Quoted with permission from Osborn, Noel D. and Hatton, Howard A. A Handbook on Exodus. (UBS Helps for Translators). New York: UBS, 1999. For this and other handbooks for translators see here .