Verses with the word oaths in the Old Testament (2 verses):

Ezekiel 21:23
And it shall be unto them as a false divination in their sight, to them that have sworn oaths: but he will call to remembrance the iniquity, that they may be taken.

Habakkuk 3:9
Thy bow was made quite naked, according to the oaths of the tribes, even thy word. Selah. Thou didst cleave the earth with rivers.