Then went up Moses, and Aaron, Nadab, and Abihu, and seventy of the elders of Israel:

Jamieson-Fausset-Brown Bible Commentary

9. Then went up Moses, and Aaron-in obedience to a command given (Ex 24:1, 2; also Ex 19:24), previous to the religious engagement of the people, now described.

Nadab, and Abihu-the two oldest sons of Aaron [Ex 6:23].

seventy of the elders-a select number; what was the principle of selection is not said; but they were the chief representatives, the most conspicuous for official rank and station, as well as for their probity and weight of character in their respective tribes.

Matthew Henry's Concise Commentary

24:9-11 The elders saw the God of Israel; they had some glimpse of his glory, though whatever they saw, it was something of which no image or picture could be made, yet enough to satisfy them that God was with them of a truth. Nothing is described but what was under his feet. The sapphires are the pavement under his feet; let us put all the wealth of this world under our feet, and not in our hearts. Thus the believer sees in the face of Jesus Christ, far clearer discoveries of the glorious justice and holiness of God, than ever he saw under terrifying convictions; and through the Saviour, holds communion with a holy God.