When the Israelites listen to the unfaithful spies at Kadesh, Yahweh threatens to smite them and begin again with Moses (Numbers 14:12), just as He threatened to do when the people worshiped the golden calf (Exodus 32:10). Moses’ response is the same: He will damage His reputation among the nations (Numbers 14:13-19; Exodus 32:11-14). In both cases, Yahweh relents (Numbers 14:20-; Exodus 32:14).
The sin at Kadesh is like the sin at Sinai, and that suggests a number of other parallels between the two incidents:
1. At Sinai, Israel worshiped a golden calf that was going to lead them. At Kadesh, they are also involved in a kind of idolatry, refusing to trust Yahweh to give them the land.
2. The twelve spies enter the land; Moses enters the cloud on the mountain. Yahweh’s land and Yahweh’s mountain are parallel, and the entry into the land is a kind of ascent to holy ground.
3. Prior to the Kadesh incident, Yahweh has given instruction for the organization of Israel’s camp. This links to the instructions in Exodus 25-31 for the construction of the tabernacle.
4. Both the golden calf incident and the rebellion at Kadesh are preceded by several rebellions by the people.
5. Both incidents are followed by instructions about the Sabbath and festivals. Exodus 34 includes a number of commands – no covenants with people of the land, smash their idols, do not make molten gods – but a good part of the chapter is taken up with instructions about sabbaths and feasts. Immediately after the Kadesh rebellion, Yahweh gives instructions about libations and grain offerings, and a man who was gathering sticks on the Sabbath is put to death (Numbers 15).
6. The next narrative in Exodus-Leviticus is about Aaron’s sons offering strange fire (Leviticus 10), and Numbers 16 records the rebellion of Korah against Aaron and the confirmation of Aaron’s priesthood.
7. After the sin of Nadab and Abihu, Leviticus gives instructions about impurity, and Numbers 19 gives the recipe for the water of purification that cleanses from corpse defilement.
No doubt there are other parallels running through these sections, but this is enough to show that Kadesh is a repetition with variation of the sin at Sinai.