when you hear the mu'adhdhin repeat what he says, invoke a blessing on me, for everyone who invoke one blessing on me will receive ten blessings from Allah. Then ask Allah to give me the wasilah, which is a rank in paradise fitting for only one of Allah’s servants, and I hope that I may be the one. If anyone asks Allah that I be given the wasilah, he will be assured of my intercession. (Using translation from Abū Dāʾūd 523)  

سَمِعْتُ رَسُولَ اللهِ ﷺ يَقُولُ «إِذَا سَمِعْتُمُ الْمُؤَذِّنَ فَقُولُوا مِثْلَ مَا يَقُولُ ثُمَّ صَلُّوا عَلَيَّ فَإِنَّهُ مَنْ صَلَّى عَلَيَّ صَلَاةً صَلَّى الله عَلَيْهِ عَشْرًا ثُمَّ سَلُوا لِي الْوَسِيلَةَ فَإِنَّهَا مَنْزِلَةٌ فِي الْجَنَّةِ لَا تَنْبَغِي إِلَّا لِعَبْدٍ مِنْ عِبَادِ اللهِ أَرْجُو أَنْ أَكُونَ أَنَا هُوَ فَمَنْ سَأَلَ لِي الْوَسِيلَةَ حَلَّتْ عَلَيْهِ الشَّفَاعَةُ»