'Abdullah bin Umm Maktum, the Mu'adhdhin (May Allah be pleased with him) reported: I said to the Messenger of Allah (PBUH): "There are many poisonous insects and wild beasts in Al-Madinah, and I am blind. Please grant me permission to perform Salat at home." He (PBUH) enquired whether he could hear the call: Hayya 'alas-Salah; Hayya 'alal-Falah (Come to the prayer, come to the salvation). When he replied in affirmative, the Messenger of Allah (PBUH) directed him to come (to mosque) for prayer."