Just before the giving of the Ten Commandments Moses reported to God that the Divine warning against Israelites ascending the mountain had been accepted, saying, “The people (know they) are not allowed to go up Mount Sinai” (Ex. 19:23). As a result, Moses himself ascended Sinai whilst the people remained at the foot of the mountain.
It’s amazing how a people that had just emerged from bondage and had not yet become a disciplined nation acknowledged that there were bounds (our generation would call them red lines) that they were not permitted to cross.
Everyone was anxious to get to the real centre of all the action, but they were told to hold back. They must have had a basic knowledge of history and would have remembered what happened at the Tower of Babel, where an attempt to storm God’s domain was so dramatically frustrated.
The lesson we learn is that there are some things which are not for ordinary mortals, especially the real truth of God. Reason can only lead us so far; beyond that there are realms which are not to be entered. It is not that they are against reason but beyond reason.
Revelation too has its limits: God reveals what He wants us to know but keeps the true secrets to Himself. As the Torah tells us towards the end of the Book of D’varim, “The secret things belong to the Lord our God: the revealed things are for us and our children to obey to eternity” (Deut. 29:28).