en_tn/1sa/30/06.md

distressed

suffering

all the people were bitter in spirit

The word "bitter" is a metaphor for the desire to rebel. The word "spirit" is a synecdoche for the person. AT: "all the people were ready to rebel against David" or "all the people were very unhappy" (See: rc://en/ta/man/translate/figs-synecdoche)

David strengthened himself in Yahweh, his God

Possible meanings are 1) "David took courage because he knew Yahweh his God would help him" or 2) "Yahweh his God made David strong."