They answered Joshua, and said, Because it was certainly told your servants, how that Yahweh your God commanded his servant Moses to give you all the land, and to destroy all the inhabitants of the land from before you; therefore we were sore afraid for our lives because of you, and have done this thing.
"The ’oath’ was made in the name of the Lord. Consequently fidelity was owed, not to the Gibeonites, but to the Lord. The form of the oath called on the Lord to punish the Israelites if they failed to keep their agreement (cf. Joshua 9:18-20). This explains why Israel felt bound to the treaty even though it had been made under false pretenses (cf. Genesis 27:35; Psalms 15:4)." [Note: Madvig, p. 299.] 