It says in the Torah that G-d spoke to the Jews on Mt. Sinai then later on in the Torah it says G-d spoke to the Jews on Mt. Horeb, so which Mt. did G-d really speak to the Jews on.
Moses called all of Israel and said to them: 'Hear, O Israel, the decrees and the ordinances that I speak in your ears today ― learn them, and be careful to perform them. The Lord your God sealed a covenant with us at Horev [Mount Sinai]. Not with our forefathers did God seal this covenant, but with us ― we who are here, all of us alive today. Face to face did God speak with you on the mountain from amid the fire.' (Deut. 5:1-4)