Albert Barnes
See Leviticus 2:3 note. It could have been only by a stretch of the law that Ahimelech gave a portion of the showbread to David and his men, on the ground that they were free from ceremonial defilement. 1 Samuel 21:4-6; Matthew 12:4.
The showbread was a true meat-offering (see Exodus 25:29). The special form in which it was offered, especially in its being brought into the tabernacle and in its consisting of twelve loaves, distinguish it as an offering made on behalf of the nation.
The offender may already have been pronounced guilty by the rulers (see Exodus 18:21-22), and the case was referred to Moses in order that the punishment might be awarded by the divine decree. No law had as yet been enacted against blasphemy except by implication. See Exodus 21:17; Exodus 22:28.
Lay their hands upon his head - As a protest against the impiety of the criminal, symbolically laying the guilt upon his head. Compare the washing of hands, Deuteronomy 21:6; Matthew 27:24.
Let all the congregation stone him - See Leviticus 20:2 note.
Stranger - i. e. foreigner. See Leviticus 16:29 note.