Musar על סנהדרין 33:1

Here, too, when they came to spy out the land, the yetzer intensified itself over them, causing them to say: "To defeat men so numerous and so strong requires great, awesome merit which we do not possess. For we have just made the golden calf and [eaten] flesh of lust. [(This, although they had already repented and had wept profusely (for their sin), as we find in Pirkei d'R. Eliezer, that on the last of the forty days of Moses' ascent to the mountain, when they knew that on the morrow he would descend from the mountain all of Israel spent the night fasting and went the next day to receive him, weeping profusely, and it was told them that the Holy One Blessed be He had forgiven them, so that [this day] was instituted for them for forgiveness for future generations)]. For this reason they said (Ibid. 27): "We came to the land to which you sent us, and it is, indeed, flowing with milk and honey, and these are its fruits (28): but the people are strong, who dwell in the land… and also the children of the giant did we see there (29): Amalek dwells in the lands of the south, etc." This, as if to say: "We need the merit of Moses our teacher, as of yore"; as if to say: "Who knows if he will live until then?" (For they had an intimation from the prophecy of Eldad and Medad (Sanhedrin 27a, 29a) [that he would die before then]). And, aside from this (Ibid.): "And the Chitti and the Yevussi, etc." That is, to defeat all of them before we come to Eretz Israel requires great merit. How much more so to come to the people in Eretz Israel and overcome them there!