Directly after handing over the book of the law, Moses directed the elders of all the tribes, together with the official persons, to gather round him, that he might rehearse to them the ode which he had written fore the people. The summons, “gather unto me,” was addressed to the persons to whom he had given the book of the law. The elders and officers, as the civil authorities of the congregation, were collected together by him to hear the ode, because they were to put it in the mouth of the people, i.e., to take care that all the nation should learn it. The words, “I will call heaven and earth as witnesses against you,” refer to the substance of the ode about to be rehearsed, which begins with an appeal to the heaven and the earth (Deu 32:1). The reason assigned for this in Deu 31:29 is a brief summary of what the Lord had said to Moses in Deu 31:16-21, and Moses thought it necessary to communicate to the representatives of the nation. “The work of your hands” refers to the idols (vid., Deu 4:28).