en_tn_condensed/amo/03/13.md

the house of Jacob

The word "house" is a metonym for the family that lives in the house. In this case it refers to Jacob's descendants. They were the people of Israel. Alternate translation: "the descendants of Jacob" (See: rc://en/ta/man/translate/figs-metonymy)

this is the declaration of the Lord Yahweh, the God of hosts

Yahweh speaks of himself by name to express the certainty of what he is declaring. See how you translated the similar phrase "this is Yahweh's declaration" in Amos 2:11. Alternate translation: "this is what the Lord Yahweh, the God of hosts, has declared" or "this is what I, the Lord Yahweh, the God of hosts, have declared" (See: rc://en/ta/man/translate/figs-123person)