Exodus 24:14

And he said unto the elders
The seventy elders which were selected out of the several tribes of Israel, and now about to return to the camp:

tarry ye here for us;
meaning himself and Joshua, who was going with him:

until we come again unto you;
perhaps Moses might not know how long his stay would be at the top of the mount, but supposed it would be some time by the provision he makes for hearing and adjusting cases in his absence:

and behold, Aaron and Hur are with you;
Hur is not mentioned before, as being with Moses and the rest; but doubtless he was, at least it is highly probable he was one of the seventy elders of him, (See Gill on Exodus 17:10).

if any man have any matters to do:
any cases to be considered, any cause to be tried in difference between him and another man, and which cannot be determined by the inferior judges, is too difficult for them to take in hand:

let him come unto them;
bring his case before them, and have their advice and opinion, and be determined by them.