Once the people of Israel crossed the Jordan River into Canaan, they would be faced with seven nations (the “-ites” of v.1), each larger and more powerful than they were — and God expected Israel to defeat them all! This sounds like an impossible demand unless you consider that God promised to “clear them away” and “give them over” to Israel (v.1-2). God was going to win victories for His people, enabling them to fight beyond their size and ability (see v.17-24). God would even use hornets (v.20) to drive their enemies out of hiding and into the open!
God called for the “complete destruction” of the seven nations (v.2). There were to be no peace treaties or deals made with them; none of them were to be left alive. Some try to soften this requirement by construing it to mean “set apart for an offering to God” (i.e., to simply pronounce, “This city/nation/people now belong to God” and then let them live). But that explanation would hardly fit the remainder of the verse, “show no mercy,” or the command in verse 16, “Your eye shall not pity them.”
Furthermore, allowing these nations to continue to live in the land would hardly fulfill God’s intentions to punish the nations of Canaan and to protect the nation of Israel. These divine objectives would only be met by totally wiping out the Canaanites and their wicked culture. Deuteronomy 9:4-5 explains that God was going to judge the wickedness of the seven nations, and the swords and spears and arrows of Israel would be His instruments of judgment.
Complete destruction of these nations would also protect Israel from their influence. If they were to spare them and intermarry with them, they would end up with homes invaded by idol-worshipers and their detestable idols (v.3-4). And so God commanded that the people be executed and that every trace of their idol worship be smashed and burned (v.5).
God made the reason for these extreme measures clear: Israel was His “chosen” people (v.6). They were obviously not chosen for what they could offer God — they were a small nation of frightened slaves when He brought them out of Egypt (v.7). They were “chosen” because God chose to love them and save them.
But Israel was not without responsibility in this matter. They would only know the blessings, protection, and empowerment of God if they obeyed His Law (v.12). The promise of God in verse 9 is beautiful, but it is conditional.