Deuteronomy 31:2-4 New Revised Standard Version (NRSV)
2 he said to them: “I am now one hundred twenty years old. I am no longer able to get about, and the Lord has told me, ‘You shall not cross over this Jordan.’ 3 The Lord your God himself will cross over before you. He will destroy these nations before you, and you shall dispossess them. Joshua also will cross over before you, as the Lord promised. 4 The Lord will do to them as he did to Sihon and Og, the kings of the Amorites, and to their land, when he destroyed them.