The Spirit, speaking of the sovereignty of God, declared, "All are your servants" (Ps 119:91). That includes all thngs animate and inanimate. It even includes empires and kings, like the Persian king, Cyrus (cf. Isa 44:28). Yet, all the things that serve God are types of the One which God calls "My righteous Servant," Jesus. By asking, "Lord, who has believed our report," Isaiah put the focus on what we must believe in order to be saved.