Passage cross-references.

And we took all his cities at that time, and utterly destroyed the men, and the women, and the little ones, of every city, we left none to remain:

Rise ye up, take your journey, and pass over the river Arnon: behold, I have given into thine hand Sihon the Amorite, king of Heshbon, and his land: begin to possess it, and contend with him in battle.

Who smote great nations, and slew mighty kings; …

Notwithstanding no devoted thing, that a man shall devote unto the LORD of all that he hath, both of man and beast, and of the field of his possession, shall be sold or redeemed: every devoted thing is most holy unto the LORD. …

And Israel vowed a vow unto the LORD, and said, If thou wilt indeed deliver this people into my hand, then I will utterly destroy their cities.

And the LORD said unto me, Fear him not: for I will deliver him, and all his people, and his land, into thy hand; and thou shalt do unto him as thou didst unto Sihon king of the Amorites, which dwelt at Heshbon.

But of the cities of these people, which the LORD thy God doth give thee for an inheritance, thou shalt save alive nothing that breatheth: …

And all the spoil of these cities, and the cattle, the children of Israel took for a prey unto themselves; but every man they smote with the edge of the sword, until they had destroyed them, neither left they any to breathe.

Sihon king of the Amorites: for his mercy endureth for ever: …