en_tn/2sa/21/01.md

sought the face of Yahweh

Here "face" is a synecdoche for Yahweh's presence. This means David prayed to Yahweh for an answer about the famine. (See: rc://en/ta/man/jit/figs-synecdoche)

because of Saul and his murderous family

Saul had killed many Gibeonites, and Saul's descendants are guilty because of this sin.