Hadrat Jabir bin Abdullah Radiallahu Anhu narrates that Rasulullah Salallahu Alaihi Wasallam said: “Whoever says the following when he hears the Adhaan, shall have my intercession on the Day of Resurrection:
اللَّهُمَّ رَبَّ هَذِهِ الدَّعْوَةِ التَّامَّةِ وَالصَّلَاةِ الْقَائِمَةِ آتِ مُحَمَّدًا الْوَسِيلَةَ وَالْفَضِيلَةَ وَابْعَثْهُ مَقَامًا مَحْمُودًا الَّذِي وَعَدْتَهُ
“O Allah! Rabb of this perfect call and eternal prayer. Grant Muhammad Salallahu Alaihi Wasallam the Wasilah (a place in Jannah), and the merit, and raise him to the praiseworthy position which You promised him.” [Sahih Bukhari]
Hadrat Abu Darda Radiallahu Anhu narrates that Rasulullah Salallahu Alaihi Wasallam used to say the following when he heard the Muazzin:
اللهم رب هذه الدعوة التامة والصلاة القائمة، صل على محمد وأعطه سؤاله يوم القيامة
“O Allah! Lord of this perfect call and eternal prayer. Send salutations to Muhammad Salallahu Alaihi Wasallam and grant him whatever he asks for on the Day of resurrection.”
Rasulullah Salallahu Alaihi Wasallam used to read the above supplication audibly so that others around him would hear it. He loved to hear others saying this supplication when they heard the Muadhin. He said: “Whoever says this when he hears the Muazzin, then intercession of Muhammad Salallahu Alaihi Wasallam becomes incumbent upon him on the Day of resurrection.” [Ja’miul Masaaneed Was Sunan]
Another narration states that when Rasulullah Salallahu Alaihi Wasallam heard the Adhaan, he would say the following:
اللَّهُمَّ رَبَّ هَذِهِ الدَّعْوَةِ التَّامَّةِ وَالصَّلَاةِ الْقَائِمَةِ، صَلِّ عَلَى مُحَمَّدٍ عَبْدِكَ وَرَسُولِكَ، وَاجْعَلْنَا فِي شَفَاعَتِهِ يَوْمَ الْقِيَامَةِ
“O Allah! Rabb of this perfect call and eternal prayer. Send salutations to Your servant and Messenger, and include us in his intercession on the Day of resurrection.” [Tabrani]
Rasulullah Salallahu Alaihi Wasallam said: “Whoever reads the above after the Adhaan, Allah Ta’ala will include him in my intercession on the Day of resurrection.” [Haithami]
Hadrat Anas Radiallahu Anhu narrates that Rasulullah Salallahu Alaihi Wasallam said: “Supplication (Dua) between the Adhaan and Iqaamah is not rejected.” [Sunan Abu Dawud]
Imaam Tirmidhi Rahimahullah adds in his narration: “The Sahaaba Radiallahu Anhum asked, ‘What should we say, O Rasulullah Salallahu Alaihi Wasallam?’ He replied, ‘Ask Allah Ta’ala for pardon and well-being in this world and in the hereafter.”