en_tn/2ch/32/31.md

the miraculous sign that had been done in the land

This can be stated in active form. Alternate translation: "the miracle that Yahweh had performed in the land" (See: rc://en/ta/man/translate/figs-activepassive)

to know all that was in his heart

Here "heart" represents a person's inner being. Alternate translation: "to reveal Hezekiah's true character" (See: rc://en/ta/man/translate/figs-metonymy)