Deuteronomy 17:8-13 -

So long as Moses was with the people, they had in him one to whom, in the last resort, eases might be brought for decision which were found too difficult for the ordinary judges ( Exodus 18:19-26 ). But, as he was not to be always with them, it was needful to provide a supreme court, to which such cases might be carried when they could no longer be decided by him; and such a court is here appointed to be held at the sanctuary.