Charles Ellicott Commentary Deuteronomy 1:9-18

"And I spake unto you at that time, saying, I am not able to bear you myself alone: Jehovah your God hath multiplied you, and, behold, ye are this day as the stars of heaven for multitude. Jehovah, the God of your fathers, make you a thousand times as many as ye are, and bless you, as he hath promised you! How can I myself alone bear your cumbrance, and your burden, and your strife? Take you wise men, and understanding, and known, according to your tribes, and I will make them heads over you. And ye answered me, and said, The thing which thou hast spoken is good [for us] to do. So I took the heads of your tribes, wise men, and known, and made them heads over you, captains of thousands, and captains of hundreds, and captains of fifties, and captains of tens, and officers, according to your tribes. And I charged your judges at that time, saying, Hear [the causes] between your brethren, and judge righteously between a man and his brother, and the sojourner that is with him. Ye shall not respect persons in judgment; ye shall hear the small and the great alike; ye shall not be afraid of the face of man; for the judgment is God`s: and the cause that is too hard for you ye shall bring unto me, and I will hear it. And I commanded you at that time all the things which ye should do." — Deuteronomy 1:9-18 (ASV)

In these words Moses appears to combine the recollection of two distinct things:

1. The advice of Jethro (Exodus 18), by following which he would be relieved from the ordinary pressure of litigation.
2. The still further relief afforded him by the appointment of the seventy elders.

These last received the gift of prophecy and were thus enabled to relieve Moses from some of the higher responsibilities of his office by representing his mind and reproducing his personal influence in many parts of the camp at once.

Jethro’s advice was given on their first arrival in Horeb: when it was carried into effect we are not told. The seventy elders were appointed (Numbers 11) between Sinai and Kadesh-barnea, shortly after they left Sinai. It is quite possible that both institutions came into existence at the same time. The seventy elders would have been of great service in the selection of the numerous judges and officers who were required.