For a long time I found some things very confusing, especially about Mt Horeb, (in the land of Moriah/Marah in the Western wilderness in Egypt) and Mt Sinai (in Arabia) how could theses two mountains be the same mountain?..
For example; Mt Horeb, (in the land of Moriah) is only a three day march in the western wilderness of Etham, in (no man's land) in the desert of Egypt, Numbers 33:8. And is called the mountain of the (true God)
Mount Moriah in Jerusalem is a lot farther away and (NOT) in the Etham Wilderness, but is in the land of Canaan, where Abraham built his first Altar, Mt Sinai is called, at Galatians 4:25. Now this Hagar means Sinai, a mountain in Arabia and she corresponds to Jerusalem today, for she is in slavery with her children.
And these two women (Sarah and Hagar) had (two sons) one born to Hagar, (which means Sinai (Ishmael) and one born to Sarah, Horeb (Isaac). the covenant with Abraham for the seed (Isaac) was made at Horeb and the covenant with Hagar's seed at Sinai.
These two sons represent two covenants, one for the Priests, (spiritual Israel) the Aaron priesthood, according to Melchizedek. Hebrews 5:6. and one for (fleshly Israel) the Jews, now living in Israel.