إجراء كلمة الكفر على اللسان مع اطمئنان القلب عند الإكراه
Uttering words of disbelief under coercion while the heart remains firm in faith.
The example separates outward speech forced by severe pressure from inward belief that remains intact. The concession concerns the combination of coercion and continued inner conviction; it is not equivalent to voluntarily adopting disbelief in both word and conviction.
The relevant distinction is the compelling threat together with assurance of faith in the heart. This does not make words contrary to one's faith inconsequential in ordinary circumstances.