The prophet in Isa. vii 9b urges Ahaz to show faith in Yhwh. But what does faith in Yhwh here entail? The two most common views are considered: a call to total passivity and a call to reject all political alliances. An alternative reading that is based on an appeal to the final form and position of Isa. vii is then proposed. Faith finds security in the word of Yhwh and rejects a religious piety that ignores the practice of righteousness and justice. This understanding of faith is in harmony with the opening message that is found in Isa. i and the emphasis on righteousness that is prominent elsewhere in the book.