In Joshua 8:1–2 God promises Joshua that he will deliver Ai into his hands, that Israel will completely destroy the city and carry off its spoil and livestock for themselves. Throughout the rest of the chapter, we see how God delivers on his promises. He reveals the battle strategy to Joshua (Joshua 8:1–8), he gives Joshua the signal to start the ambush (Joshua 8:18), the city and its inhabitants are destroyed (Joshua 8:26), and the people carry off spoil and livestock (Joshua 8:27). The Lord said he would defeat Ai and give the Israelites victory, and that is what he has done. The Lord is faithful to his promises.

In Joshua 8:29 we are told that the king of Ai is hung on a tree. According to Deuteronomy 21:23, this testifies to the fact that he is under the curse of God. God’s curse is upon him and all his people. God had previously promised Abraham that his descendants would be the means by which he comes to judge the sins of the Amorites (Genesis 15:16). The people of Israel must destroy them for they are under God’s curse on account of their sins (cf. Leviticus 18:1–30; Deuteronomy 20:16–18). With the death of the king of Ai, we have a testimony that God’s promised judgment of the Amorites has come. The Lord is faithful to his promises.

In Deuteronomy 28:7, the Lord promised Israel that under the terms of the Mosaic covenant, he would destroy their enemies if they were obedient to him. He would cause their enemies to flee seven ways before them; they would be utterly destroyed. In Joshua 8:20–22 as well as Joshua 8:26, we are told that the enemies of Israel flee before them and they are completely destroyed. The Lord is faithful to his promises.

Thus, in the defeat of Ai, in the hanging of their king on the tree, and in the complete victory of Israel, we have three testimonies that the Lord is faithful to his promises. He does exactly what he says he will do.