A False testimony of Faith [hypocrisy and the shahadah]

The likeness [of the munāfiq] is as the likeness of one who kindled a fire; then, when it lighted all around him, Allāh took away their light and left them in darkness. So they could not see. They are deaf, dumb and blind, so they return not [to the Right Path]. (Quran 2:17)

Qatādah – Allāh’s mercy be upon him – said: This is the likeness Allāh has given of the Hypocrite (munāfiq); he says lā ilāha illallāh and with it marries into the Muslims, inherits from the Muslims, fights alongside the Muslims, and protects his blood and wealth. But when death comes, [the testimony of faith] has no basis in his heart, and no reality in his actions, so the munāfiq is stripped of it at death and left in darkness and blindness wondering therein, just as he was blind about the right of Allāh and obedience to Him in his worldly life and deaf to the truth. Al-Ṭabarī, Al-Tafsīr.

Al-Ṭabarī, Al-Tafsīr.