Exodus 19:22

(22) The priests.—This has been called an anachronism, since the Levitical priesthood was not as yet instituted. But the Israelites, like all other ancient tribes or races, must have had priests long ere this, appointed upon one principle or another. It is a reasonable conjecture that hitherto the heads of families had exercised sacerdotal functions.

Break forth—i.e., punish in some open and manifest way. Compare the “breach” upon Uzzah (2 Samuel 6:8).