How else is the verb for "broke faith" used in Scripture?
The Hebrew text makes use of a very strong word for sin here. The Hebrew word elsewhere describes adultery (Numbers 5:12–13), and can also denote the idea of purposeful rebellion incurring the wrath of God (cf. 1 Chronicles 10:13–14).1
1 But the people of Israel broke faith in regard to the devoted things, for Achan the son of Carmi, son of Zabdi, son of Zerah, of the tribe of Judah, took some of the devoted things. And the anger of the LORD burned against the people of Israel.