אור החיים — ומשה עלה אל האלהים

Q — Verse 3 says 'Moshe ascended to God, and the Lord called to him from the mountain' — but shouldn't the calling precede the ascent, since surely Moshe would not climb before being summoned? Ibn Ezra solves it by reading 'ויקרא' as 'had already called.'

A — Or HaChaim takes the order at face value — Moshe really did ascend before being called — and asks why. His answer: at the burning bush God had already told Moshe 'when you bring the people out of Egypt you shall serve God on this mountain,' designating Sinai as the place of receiving the Torah. Knowing in advance that this was the appointed site, Moshe ascended on his own initiative, and only then was he called.