This refers to seeing what was in the land. Alternate translation: "They saw the strong people and cities in the land" (See: [[rc://en/ta/man/translate/figs-explicit]])
Here the word "hearts" represents the people themselves and refers to the seat of their emotions. See how you translated this in [Numbers 32:7](../32/07.md). Alternate translation: "discouraged the people of Israel" (See: [[rc://en/ta/man/translate/figs-synecdoche]])