Verses 20-25:
This text illustrates the power of intercessory prayer, from the heart of a truly humble mediator, see Jas 5:16. God pardoned Israel at Moses’ request, 2Co 1:3, 4.
Verse 21 could read, "As truly as I live, and (as truly as) the glory of the Lord shall fill all the earth."
"Because," biy, a particle which introduces the substance of God’s oath, "As I live. . .all those men ...shall not see the land." This refers to those regarded as mature men who witnessed the miracles in Egypt, Israel’s deliverance, and the wilderness miracles up to the arrival at Kadesh.
Caleb alone is mentioned as exempt from the oath of Divine judgment pronounced upon Israel’s men. Joshua’s name was likely omitted because he was already recognized as Moses; heirapparent. He and Caleb were the two of the twelve spies who urged immediate occupation of the Land of Promise.
No specific allotment was promised to Caleb at this time.
This text illustrates the sure reward for faithfulness, and the certain judgment for unfaithfulness.
God’s command: "tomorrow," the next day, Israel was to resume their march, this time back-tracking into the Sinai peninsula, in the direction of the Red Sea and away from the Land of Promise. They temporarily forfeited their inheritance, which God had assured them, by their unbelief.