Parashas Eikev · Passuk 9:9
I had ascended the mountain to receive the tablets of stone, the Tablets of the Covenant that GOD had made with you, and I stayed on the mountain forty days and forty nights, eating no bread and drinking no water.
Torah Temimah points to Megillah 21b.
TT lemma: ואשב בהר.
English: “I sat on the mountain,” while above it says “I stood on the mountain.” Rav said: one stands while learning [new material] and sits while reviewing. R’ Chanina said: he was bowing. R’ Yochanan said: “sitting” here means only delay, as in “you stayed in Kadesh many days.” Rava said: easy material standing, difficult material sitting — soft matters that the ear grasps quickly are learned standing; hard matters that need toil may be studied sitting. (Leaning while “standing” can count as sitting for some laws of Torah reading.)
Dispute (how Moshe “sat” / “stood” on the mountain)
The dual language of sitting and standing on the mountain is resolved as modes of study, or as delay, or as posture.