Yahweh is speaking.

## I knew you in the wilderness ##

Yahweh, unlike the gods of the idols, watched over his people and blessed them with water and what they needed to survive in the desert.

## your heart became lifted up ##

"Your heart" refers to the relationship of the people of Israel toward God; they became proud, thinking that they did not need Yahweh to be their god any more. (see: [[rc://en/ta/man/translate/figs-metonymy]])