26I call heaven and earth to witness against you today, that you will soon utterly perish from the land that you are going over the Jordan to possess.You will not live long in it, but will be utterly destroyed.
Moses calls upon the heavens and the earth to be covenant witnesses to the curse, which would come into effect if the Israelites did not obey the terms of the covenant. Such faithlessness would lead to suffering, ultimately destruction.
26 I call heaven and earth to witness against you today, that you will soon utterly perish from the land that you are going over the Jordan to possess. You will not live long in it, but will be utterly destroyed.