Where can the second narration from Abu Hanifa be found regarding the definition of faith, which states that faith is "attestation" (تصديق), and what is its chain of transmission?

What is well-known about Imam Abu Hanifa is that faith (Iman) is affirmation and تصديق (assent/belief). There is another narration attributed to him—widespread in Hanafi books—that verbal affirmation (إقرار باللسان) is a condition for the application of rulings (إجراء الأحكام). However, the authenticity of this narration attributed to him requires a chain of transmission (Isnad (definition)) or a text from a knowledgeable scholar. Both narrations contradict the stance of Ahl al-Sunnah (definition) wal-Jama'ah, which is that faith is statement and action, increasing with obedience and decreasing with disobedience.