How did the spies succeed in instilling fear in the hearts of the Israelites to the extent that the entire people cried bitterly?

Once the spies returned from scouting the land, they got up and spread out among all the tribes of Israel, each spy to his tribe. He would fall in each corner of his house, distraught, and his sons and daughters would come and say to him: What is it, my master? While attempting to stand, he would feign falling before them. He would say to them: Woe is me over you, my sons, daughters, and daughters-in-law. How those Emorites are going to mock you; how they are going to rule over you; who can withstand them?... Immediately, they would all begin weeping loudly, their sons, their daughters, and their daughters-in-law, until the neighbors heard it. And they too would cry, until each family would be heard by the next, and until the entire tribe was weeping. Likewise, each spy would cause his tribe to weep, and each and every one did the same until all 600,000 men became one unit, and they wept bitterly and cried out to the heavens. (Yalkut Shimoni, Shelah 1:743)