Charles Ellicott Commentary Exodus 24:4

"And Moses wrote all the words of Jehovah, and rose up early in the morning, and builded an altar under the mount, and twelve pillars, according to the twelve tribes of Israel." — Exodus 24:4 (ASV)

Moses wrote. —Compare Exodus 17:14. The familiarity of Moses with writing is presumed throughout the Pentateuch. One “learned in all the wisdom of the Egyptians” under the nineteenth dynasty could hardly be ignorant of this ordinary Egyptian accomplishment.

Under the hill. —Hebrew, the mountain. The Ras Sufsafeh is intended.

Twelve pillars. —As the altar symbolized and indicated the presence of Jehovah, one party to the Covenant, so the twelve pillars—probably long stones set up on end (Genesis 28:18)—symbolized the presence of the twelve tribes, the other party. (For another instance of the employment of such symbolism see Joshua 4:3; Joshua 4:9; Joshua 4:20.)