Why Moses Waited to Rebuke Israel Until After Sihon and Og Fell

"After he had smitten Sihon king of the Amorites" (Deuteronomy 1:4). And why did he not rebuke them before this? Only so that Israel should not say: "He has not yet done us any good, and [already] he has begun to rebuke us." And why did he wait until close to his death? For this reason that we have stated: Come and see the humility of the Holy One, blessed be He, for He showed a good way to the world, that the student says to the teacher, "I have wearied you greatly." And therefore the Holy One, blessed be He, waited until He had smitten Sihon and Og, and then He rebuked them. But the Holy One, blessed be He, said to them, "You have dwelt long enough at this mountain" (Deuteronomy 1:6) — that is to say: I have detained you a long time at this Mount Sinai.