Midrasz do Liczb 21:33

..."Do not fear him" - this is [the meaning of] that which Scripture stated (Proverbs 28:14), "Happy is the man who always fears." And this is the trait of the righteous: even though the Holy One, blessed be He, reassures them, they do not relinquish fear. And so [was it] with Jacob - "and Jacob feared" (Genesis 32:8). Why did he fear? He said, "Maybe I have been tarnished by something [when I was] with Laban... so the Holy One, blessed be He, abandoned me." And so too did Moses take hold of fear corresponding to his [fore] father. And why did he fear? He said, "Maybe Israel misappropriated [some goods] in the war with Sichon or became tarnished with a sin." The Holy One, blessed be He, said to him, "Do not fear"...

(Numb. 21:25:) “Israel took all these towns….” This text is related (to Is. 61:8), “Because I the Lord love justice, I hate robbery with a burnt offering.”¹⁵²Numb. R. 19:30. The Holy One, blessed be He, said to Moses (in Deut. 2:9), “Do not trouble Moab.” Now Heshbon had been part of Moab, since it is stated (in Numb. 21:26), “For Heshbon was a city of Sihon king of the Amorites,” but he had fought against the former king of Moab [and taken all his land away from him as far as the Arnon]. When Israel came, they took Heshbon, which belonged to Sihon and whatever [else] he had taken from the king of Moab. For if they had taken it from him [directly], they would have had major robbery on their hands. Instead Sihon took it from Moab, and Israel took it from Sihon. Thus they were acquitted from [the charge of] robbery. Therefore it is written (in Numb. 21:26), “For Heshbon was a city of Sihon.” (Numb. 21:27:) “Therefore those who speak in parables say.” This refers to Balaam and his father, whom Sihon had hired to curse Moab. And it was they who had said (Numbers 21:27-8), “[Come to Heshbon,] let it be built; let the city of Sihon be established. For a fire has come forth from Heshbon, [a flame from the city of Sihon]. It has devoured Ar [of Moab].” Thus they cursed Moab so that they might deliver it into [Sihon's] hand. (Numb. 21:29-31:) “Woe be to you, O Moab…. Yet we have cast them down; Heshbon has perished…. Thus Israel dwelt (in all the cities) [in the land of] the Amorites.” [Only] Jazer survived.¹⁵³Numb. R. 19:31. (Numb. 21:32:) “So Moses sent to spy out Jazer.” These spies were zealous. They said, “We have confidence in the prayer of Moses. [Yet] he has already sent messengers [that were] spies in the past and they brought a catastrophe. But we shall not do so. Rather, we will trust in the Holy One, blessed be He, and make war.” They then did so and slew the Amorites who were in [the city]. (Numb. 21:33), “Then they turned and went up […].” What is the meaning of “Then they turned and went up?” R. Johanan says, “The wars of Sihon took place in Elul. Then they celebrated the festival in Tishri,¹⁵⁴Numb. R. 19:32. then after the festival came the war with Og. [Just as you say with regard to the festival of Passover] (in Deut. 16:7), “and in the morning you shall turn to your tents.” (Numb. 21:33, cont.:) “And Og king of Bashan came out against them, he and all his people,” for the Holy One, blessed be He, had gathered [them all] before [Israel] in order to deliver [Og and his people] into their hand.