Deuteronomy 20:20
Only the trees which thou knowest that they be not trees for meat, thou shalt destroy and cut them down; and thou shalt build bulwarks against the city that maketh war with thee, until it be subdued.
Cross-references
In Ecclesiastes 9:14, a great king builds siegeworks against a city, directly illustrating the siege tactic permitted here.
In Jeremiah 6:6, God commands cutting trees and casting up a siege mound against Jerusalem, echoing the law's instructions for siege warfare.
In 2 Kings 3:19, Israel is commanded to fell every good tree — directly contradicting the prohibition against cutting fruit trees here.
In 2 Kings 3:25, the army fells all good trees — a practical violation of the law that spares fruit trees for food.
In 2 Chronicles 26:15, Uzziah builds siege engines — a practical application of the permission to cut trees for siegeworks.
In Isaiah 37:33, God promises the Assyrian king will not cast up a siege mound — the same term for the siegeworks allowed here.
In Ezekiel 17:17, siege mounds are cast up in war, matching the siegeworks described here as a standard military tactic.