حِصْنُ الْمُسْلِمِ
Hisn al-Muslim 22
Fortress of the Muslim (Hisn al-Muslim)
Concerning the athan (the call to prayer)
يقول مثل ما يقول المؤذن إلا في (حي على الصلاة ، وحي على الفلاح) فيقول لا حول ولا قوة إلا بالله.
Repeat what the Mu'adh-dhin says, except for when he says: Hayya 'alas-Salāh (hasten to the prayer) and Hayya 'alal-Falāh (hasten to salvation). Here you should say: Lā ḥawla wa lā quwwata 'illā billāh. There is no might and no power except by Allah. Reference: Al-Bukhari 1/152, Muslim 1/288.
Hisn al-Muslim, 22