Mat 12:5 Or have you not read in the law, how that on the sabbath days the priests in the temple profane the sabbath, and are blameless?

"Law" is nomos, which means "that which is in habitual usage," "custom," and "tradition." The word's translation to the "laws of God" is a special use from the Bible. The sense is much more how the books of the Old Testament are the "traditions of God."

"The priests" is hiereus, which means literally "holy man," but also "priest," "sacrificer," and "diviner." "The temple" is a related word, hieron, which means literally "holy place" or "temple." Both come from the word hieros, which means "super-human," "mighty," "divine," "wonderful" and "holy." I particularly like the idea of using the word, "wonderful" here. This make "holy man" a "wonderful man" and a "holy place," a "wonderful place."

"Profane" is bebêloô, which means "to pullute" and "to defile" especially meant to refer to the Sabbath.

"Blameless" is anaitios, which means "not being at fault," "guiltless," and "not being the cause" of something. It means literally "not the cause."

Here, Christ separates actions from the cause of those actions. In other words, he says it is the motivation that creates sin, not the action itself. This is an critical idea and one where Christianity departed from Jewish traditions. Tradition judged people by outward actions. By saying that it was the inward motivations, Christ is saying that one person cannot judge another person morally, because we cannot see into their soul.

This is very consistent with Christ message of separating social judgments, where he constantly recognizes that judgments are necessary, from spiritual judgment, which are restricted to God.