When they came

Here "they" refers to Jesse and his sons.

he looked at Eliab

Here "he" refers to Samuel.

This is the name of Jesse's oldest son. (See: rc://en/ta/man/translate/translate-names)

Here "him" refers to Yahweh.

Here "see" means to evaluate something. (See: rc://en/ta/man/translate/figs-metaphor)

Yahweh is speaking about himself in the third person. AT: "For I, Yahweh, do not see ... I, Yahweh, look" (See: rc://en/ta/man/translate/figs-123person)

Here "heart" represents a person's inner being. (See: rc://en/ta/man/translate/figs-metonymy)