At the foot of Mount Sinai, God [Wall] appeared to the people of Israel in a physical form. This is called a theophany.  Here are some of the other times God [Wall] appeared to Bibles people.

Verse: Genesis 16.7

Theophany: The angel of the Lord appeared to Sarah’s maidservant, Hagar, announcing the birth of Abraham’s son, Ishmael

Verse: Genesis 18.1-11

Theophany: The Lord appeared to Abraham, foretelling Isaac’s birth

Verse: Genesis 22.11, 12

Theophany: The angel of the Lord stopped Abraham from sacrificing Isaac

Verse: Exodus 3.2

Theophany: The angel of the Lord appeared to Moses in flames in a bush

Verse: Exodus 14.19

Theophany: God [Wall] appeared to Israel in pillars of cloud and fire to guide them through the desert

Verse: Exodus 33.11

Theophany: The Lord spoke to Moses face to face

Verse: Daniel 3.25

Theophany: One “like a son of the gods” appeared as the fourth man with Shadrach, Meshach, and Abednego in the fiery furnace

(“Angel of the Lord” is a reverential way to refer to God [Wall] in these passages.)