After the adhan, it is recommended to say the following dua (supplication):
Allahumma rabba hadhihi-d-da‘awati-t-tammati wa-s-Salati-l-qa’imati, ati Muhammadan il-wasilata wa-l-fadilata (wa-d-darajata-r-rafî‘ati) wa-b‘ath-hu maqamam mahmudan illadhi wa‘adtahu (innaka la tukhliful mi'ad)
0 Allah, Lord of this most perfect call, and of the Prayer that is about to be established, grant to Muhammad the favor of nearness (to You) and excellence and a place of distinction, and exalt him to a position of glory that You have promised him.
This dua has variations which include 'wa-d-darajata-r-rafî‘ati' and 'innaka la tukhlifu'l mi'ad'.
The addition of "innaka la tukhlifu'l mi'ad" in the supplication was narrated by Imam Bayhaqi in his Sunan, and accepted for action by the fuqaha, as mentioned by Ibn Abidin in Radd al-Muhtar, quoting Shurunbulali's Imdad al-Fattah and Ibn al-Humam's Fath al-Qadir.
- Narrated by Jabir bin 'Abdullah : Allah's Messenger  said "Whoever after listening to the adhan says (dua is given above) then intercession for me will be permitted for him on the Day of Resurrection".
[Sahih Bukhari - Book 11:588]
- Abdullah bin `Amr bin Al-`As  reported: I heard the Messenger of Allah (PBUH) saying, "When you hear the Adhan, repeat what the Mu'adhdhin says. Then ask Allah to exalt my mention because everyone who does so will receive in return ten rewards from Allah. Then beseech Allah to grant me Al-Wasilah (which is said on the dua above), which is a high rank in Jannah, fitting for only one of Allah's slaves; and I hope that I will be that man. If any one asks Al-Wasilah for me, it becomes incumbent upon me to intercede for him.'