John Gill Commentary Joshua 10:4

"Come up unto me, and help me, and let us smite Gibeon; for it hath made peace with Joshua and with the children of Israel." — Joshua 10:4 (ASV)

Come up unto me, and help me, that we may smite Gibeon
For which he thought himself not a match, not only because it was a great city, and full of mighty men, and had other cities subject to it, but because he might reasonably judge that Joshua would come to their assistance if possible, being in league with him; he sends to these kings in an authoritative manner, as if they were in some respects subject to him; and he proposes Jerusalem as the place of their rendezvous, and which it seems lay higher than their cities, though they were in the mountainous part of the country:

for it has made peace with Joshua, and with the children of Israel ;
their avowed enemies, and so had separated themselves from their countrymen, and from their common interest; and therefore it was thought proper to make an example of them, that others might fear to do the same.