Deuteronomy 9:28

lest the land whence Thou broughtest us out say, Because the Lord was not able to bring them into the land which he promised them, and because he hated them, he hath brought them out to slay them in the wilderness. Moses wants the honor of Jehovah, His reputation for love toward His people, unstained before the heathen nations, even if Israel thought so little of that honor.