The World Federation One Stop Fiqh

Ruling 939

If due to some reason one has become dumb or has some speech impediment that prevents him from saying ‘allāhu akbar’, he must say it in whatever way he can. If he cannot say the takbīr at all, he must say it in his heart and indicate with his finger in a manner that suitably conveys the words, and he must also move his tongue and lips if he can. As for someone born dumb, he must move his tongue and lips in a manner that resembles someone pronouncing the takbīr while also indicating with his finger.