Numbers 20:18
And Edom said unto him, Thou shalt not pass by me, lest I come out against thee with the sword.
Cross-reference
Numbers 20:20
Parallel
Numbers 20:20 shows Edom carrying out the threat from verse 18 by mustering a strong army to block Israel's passage.
Numbers 21:4
Historical context
Numbers 21:4 records the direct consequence—Israel must detour around Edom, leading to discouragement and complaint.