Sheikh M. S. Al-Munajjid, a prominent Saudi Muslim lecturer and author states that: “Ibn Qudamah quoted Al-Khirqi as saying that if a butcher is mute, then he may point to the sky, as a sign of seeking Allah’s blessings to the animal he slaughters.
Ibn Al-Mundhir said: All of the scholars from whom we gained knowledge were agreed that meat slaughtered by a mute person is Halal. Those scholars include Al-Layth, Ash-Shafi`i, Ishaq and Abu Thawr. This is also the view of Ash-Shu`bi, Qutadah and Al-Hasan ibn Salih.
Accordingly, the mute butcher should point towards the sky, because this gesture will take the place of speaking. His pointing towards the sky indicates that he intends to mention the name of Allah.
This is also indicated by the Hadith of Abu Hurayrah that: “A man brought a non-Arab slave woman to the Messenger of Allah, peace and blessings be upon him, and said, ‘O Messenger of Allah, I have to free a believing slave; shall I free this woman?’ The Messenger of Allah, peace and blessings be upon him, asked her: ‘Where is Allah?’ She pointed to the sky. He said, ‘Who am I?’ She pointed to the Messenger of Allah, peace and blessings be upon him, then to the sky, meaning that he was the Messenger of Allah. The Messenger of Allah, peace and blessings be upon him, said: ‘Set her free, for she is a believer.’” (Reported by Imam Ahmad)
The Messenger of Allah, peace and blessings be upon him, ruled that she was a believer on the basis of her pointing towards the sky, for her belief that Allah is above the heavens. So this should be sufficient as a sign of mentioning the name of Allah.
Given all this, if the mute butcher makes a gesture that indicates mentioning the name of Allah, and that is known, then that is sufficient to make the slaughtered meat Halal.” Al-Mughni, 9/323.