My mother-in-law stumped me with this question. Why did God allow David to eat the bread which was lawful only for the priests, but condemn Saul for offering a sacrifice, which also was lawful only for the priests?  I'm thinking it may have to do with the priest giving permission to David, whereas Saul had the previous examples from Moses' day of disastrous consequences for taking on a priestly role in offerings to God.

I guess I see the cases being different: Saul was basically impersonating a priest, not acting out of faith, while David's actions seem more innocent. He was not making an offering, just eating leftovers.

I suspect, however, that the deeper principle has to do with Law. Jesus is Lord of the Sabbath. His great-great-…great grandfather, who represents him in so many ways, understood something about grace, law, and flexibility. Maybe it was okay for David because it would have been okay for the Son of David.

We all struggle with the relationship between law and grace. I know I do, and I bet just about every Christ-follower has to work through these things at some point. Hopefully this helps!