John Gill Commentary Exodus 24:9

"Then went up Moses, and Aaron, Nadab, and Abihu, and seventy of the elders of Israel." — Exodus 24:9 (ASV)

Then went up Moses and Aaron, Nadab and Abihu
After the above things were done, the words of the Lord were told the people, and the book of the covenant read to them, to which they agreed, sacrifices were offered, and the blood of them sprinkled on the altar, and on the people. The Samaritan version adds to these, Eleazar and Ithamar, the two younger sons of Aaron:

and seventy of the elders of Israel ,
who were called up to the mountain to the Lord, (Exodus 24:1) .