Some persons say that it is Bidah (innovation) to go through the Durud Sharif before & after the Azaan.
The Ahle Sunnah Wal Jama’at considers that it is allowable to read the Durud Sharif before & after the Azaan. This is a existing practice in several of the Arab nations.
The next Quranic verse commands us to send Durud and Salam upon the Holy Prophet sallal laahu alaihi wasallam and no particular time has been set apart for this. Allah Ta’ala says:
“O ye who Believe! Send Durud and Salams upon him in abundance.” (Part 22, Ruku 4)
The Holy Prophet Muhammad sallal laahu alaihi wasallam said that when we hear the voice of the Muazzin, we should do whatever he has said & then send Durood Shareef upon him. He said that the person who sends one Durood upon him, Allah Taala will send ten mercies upon that individual. (Sahih Muslim, Al-Qaulul Badi)
In this Hadith Shareif, proof is found here that the Holy Prophet sallal laahu alaihi wasallam asked us to recite the Durood Shareef after the Azaan.
The Holy Prophet Muhammad sallal laahu alaihi wasallam said: “If, when doing any best deed you do not continue with the praise of Allah and send Durud upon me, then that deed is vacant of blessings.” (Al Jaame Sagheer) Which Muslim is there who does not think about the Azaan to be a good action?
In fact it was Salahud deen Ayubi radi Allahu anhu who gave the control of Durood Shareef to be recited just before and after the Azaan. Hazrat Salahud’deen Ayubi (radi Allahu anhu) was a very wonderful and pious King who separated the Baitul Muqaddas. Great Muhaqiqeen and Muhaditheen made Du’as for him.
Hazrat Qaazi Iyaz (radi Allahu anhu) said that it is allowable to read Durood Sharif at the time of Azaan. He says, “And from among the events on which Durood should be sent, one of them is at the time of remembering him (Prophet Muhammad sallal laahu alaihi wasallam), when getting or writing his blessed name or at the time of Azaan.” (Shifa Shareef)
Thus, to recite Durood Shareef before and after the Azaan is totally permissible and those who follow this are the Ahle Sunnah Wal Jama’at.