According to the Jahmiyya, is faith merely knowledge, or is it assent?

The Jahmiyyah define faith as knowledge in the heart only, and this is a corrupt saying because its logical consequence is that Pharaoh, his people, and Iblis were believers, even though they knew the truth but rejected it. As for the Ahlus-Sunnah wal-Hadith, faith is affirmation by the heart, utterance by the tongue, and action by the limbs.