Rashi on Exodus 19:17/רש"י על שמות י״ט:י״ז

1לקראת האלהים [AND MOSES BROUGHT FORTH THE PEOPLE …] TO MEET GOD — This (the word לקראת, “to meet”, which is used when two persons are approaching one another) tells us that the Shechina was going forth to meet them, as a bridegroom who goes forth to meet his bride. This is what Scripture means when it says, (Deuteronomy 33:2) “The Lord came from Sinai”, and it is not said, “[The Lord came to Sinai” (Mekhilta).

2בתחתית ההר AT THE NETHER PART OF THE MOUNTAIN — According to its literal meaning this signifies “at the foot of the mountain”. But a Midrashic explanation is, that the mountain was plucked up from its place and was arched over them as a cask, so that they were standing בתחתית beneath (under) the mountain itself (Mekhilta; Shabbat 88a).