1 Kings 2:28
Then tidings came to Joab: for Joab had turned after Adonijah, though he turned not after Absalom. And Joab fled unto the tabernacle of the Lord, and caught hold on the horns of the altar.
Cross-reference
1 Kings 2:6 records David's command to punish Joab, providing the reason he flees to the altar.
1 Kings 1:7 shows Joab conspiring with Adonijah, which is the reason he is now in danger and flees to the altar.
1 Kings 1:50 describes Adonijah seizing the altar horns for refuge — Joab repeats the same desperate act, showing a pattern.
2 Samuel 18:14 shows Joab killing Absalom, proving his loyalty to David during Absalom's revolt — the very loyalty mentioned in the main verse.
Exodus 21:14 directly states that a deliberate murderer taken from the altar shall be put to death — exactly Joab's situation.
Numbers 35:31 forbids accepting ransom for a murderer, reinforcing that Joab cannot escape execution.
Genesis 9:6 establishes blood-guilt for murder, underlying why Joab's refuge at the altar fails.