Reflect on the New Covenant, under which God leads and guides us by His Holy Spirit, enabling us to perceive, to see, and to hear His Word. The Israelite people were 38 or 40 years in the wilderness in the presence of God, yet they did not get it! It never sank in because God did not perform what would have given them the ability to perceive what was happening in their lives spiritually.
This is confirmed in Deuteronomy 5:29, near the end of the chapter that contains the second recording of the Ten Commandments. Moses writes:
Oh, that they had such a heart in them that they would fear Me and always keep all My commandments, that it might be well with them and with their children forever!
a precious few of those Israelites, nobody received God's Holy Spirit under the Old Covenant.
John W. Ritenbaugh
Pentecost and the Holy Spirit