But the people whine, "No! Only YHWH will we serve" (vs 21)! At this, Joshua fixes the people with a final and terrible warning. Very well, he says, "You are witnesses against your selves that you have chosen YHWH to serve him" (vs 22). In other words, their deeds will be forever a witness that their choice of YHWH is both forever and forever evaluated by what they do. And the people agree to this; " we are witnesses," they say.
Still (!), Joshua is not fully convinced by their words. "Now reject the foreign gods that are among you and direct your hearts to YHWH, God of Israel" (vs 23). Apparently, during this entire dialogue "foreign gods" have been lurking in the tents of the Israelite army! And Joshua will have none of it. And still another time the people of Israel make an avowal of obedience; "YHWH our God we will serve; only YHWH we will obey" (vs 24).
Even that is not enough for the suspicious and careful Joshua. He first writes the words of the people, and the covenant he has made with them "in the book of the Torah of God, " and then sets up a "large stone under the oak which is at the holy place of YHWH" (vs 26). He then offers one final warning. "Look! This stone shall be a witness against us, for it has heard all the words of YHWH that God spoke to us. Hence, it will be a witness against you if you lie to God" (vs 27). And finally Joshua allows the people to leave Shechem.
But surely this drama has revealed several important things. The people are simply not to be trusted! They may claim belief, but Joshua knows all too well that talk is cheap and obedience is costly. Also, YHWH is a demanding God, expecting true and single-minded loyalty from those who claim to serve. Joshua's words are in fact prophetic in several of the senses of the word. Most especially, the people's claims to obey YHWH will be again and again tested throughout Israel's subsequent history. And what about us? The stone at Shechem still stands as witness against all those who profess belief and service but too often turn to the gods beyond the river who are ever ready to offer things to us too beautiful and too enticing to pass up. We need to hear again and again the careful warnings of Joshua on the hills of Shechem; their echo still sounds.