1 Samuel 21:6
So the priest gave him hallowed bread: for there was no bread there but the shewbread, that was taken from before the Lord, to put hot bread in the day when it was taken away.
Cross-reference
In 1 Samuel 21:4, the priest explains the holy bread is available only if the men are ceremonially clean — setting the condition David meets.
1 Samuel 22:10 records Doeg's report to Saul about Ahimelech giving David bread — directly leading to the massacre of the priests.
Leviticus 24:5-9 establishes the showbread as holy and reserved for priests, the law David's action appears to break.
Matthew 12:3 directly cites this event where David ate the showbread, using it to defend his disciples.
Matthew 12:4 recounts David eating the showbread, the very act described here.
Mark 2:25-27 recounts the same event and adds Jesus' teaching that human need overrides ceremonial law.
Luke 6:4 continues the citation, describing David's action of eating the showbread.
Exodus 25:30 establishes the showbread as a perpetual offering — the very bread David ate, showing its sacred origin.
Leviticus 22:10 forbids outsiders from eating holy food — highlighting the legal barrier David crossed, later justified by need.
Leviticus 24:9 specifies that only Aaron's sons may eat the showbread — the very rule David's situation tests.