Charles Ellicott Commentary Exodus 24:14

"And he said unto the elders, Tarry ye here for us, until we come again unto you: and, behold, Aaron and Hur are with you: whosoever hath a cause, let him come near unto them." — Exodus 24:14 (ASV)

He said to the elders. —Moses understood that his stay on the mountain was about to be prolonged . He therefore prudently determined to make arrangements for the government and direction of the people during his absence. Aaron his brother, and Hur, the father of Bezaleel (perhaps his brother-in-law), seemed to him the fittest persons to exercise authority over the people during his absence; and accordingly he named them as the persons to whom appeal should be made in any difficult circumstances.

Here. —In the plain below the mountain. The injunction was that the camp should not be moved until Moses came down, however long he might be detained by the divine conversation.