Matthew Poole and continuators on Exodus 24:1

1 AND he said unto Moses, Come up unto the LORD, thou and Aaron, Nadab and Abihu , and seventy of the Elders of Israel : and worship ye afar off .

After thou hast gone down and acquainted the people with my will, and received their answer, then come up again. This sence is gathered from the repetition of this command after that was done, ver. 12.

Aaron and his two eldest sons, whom by this special honour and favour he prepared for that office to which they were to be called, chap. 28.

Not the seventy governours which were chosen after this time, as appears from Num. 11. 24. compared with Numb. 33. 16. but seventy persons selected by Moses out of those rulers chosen and mentioned Exod. 18. 25. and possibly these were the chief heads of those several families which went with Iacob into Egypt, which were about 70. See Gen. 46. 26, 27.

Though they may come up into the mount further than the people, yet do thou, and let them especially, keep their distance; and what worship either thou or they shall offer to me, shall be performed afar off from the top of the mountain whither thou onely shalt be admitted and that not to pray to me but onely to receive laws and oracles from me. See ver. 2.