Saying Aqaamaha Allahu wa adaamaha (May Allah make is continually established) when the muezzin says Qad qaamat il-salaah (Prayer is about to begin)
Question

When the muezzin says, Qad qaamat il-salaah (Prayer is about to begin),I hear some people saying Aqaamaha Allahu wa adaamaha (May Allah make is continually established). Is it Sunnah to say this?.
Praise be to Allah.The scholars differed as to whether it is mustahabb to respond to the muezzin when he recites the iqaamah before prayer. This has been discussed in the answer to question no. 111791. 
According to the view that it is mustahabb to respond to the muezzin when he recites the iqaamah as with the adhaan, then one should say Qad qaamat il-salaah (Prayer is about to begin) and not Aqaamaha Allahu wa adaamaha (May Allah make is continually established). 
Because the Prophet (peace and blessings of Allah be upon him) enjoined us to say what the muezzin says, and there is no valid report about any exception apart from when the muezzin says Hayya ‘ala al-salaah, hayya ‘ala al-falaah (come to prayer, come to prosperity), when we should say La hawla wa quwwata ila Billaah (there is no power and no strength except with Allah). 
With regard to the hadeeth narrated by Abu Dawood (528) from Abu Umaamah (may Allah be pleased with him) or from some of the companions of the Prophet (peace and blessings of Allah be upon him), which says that Bilaal began to recite the iqaamah, and when he said Qad qaamat il-salaah (Prayer is about to begin), the Prophet (peace and blessings of Allah be upon him) said: Aqaamaha Allahu wa adaamaha (May Allah make is continually established), this is a da’eef (weak) hadeeth that is not saheeh. 
Al-Albaani (may Allah have mercy on him) said: 
This isnaad is weak. Muhammad ibn Thaabit, who is al-‘Abdi, is da’eef (weak), and so is Shahr ibn Hawshab, and the man between them is unknown. 
Irwa’ al-Ghaleel (241). 
This was classed as da’eef by al-Nawawi in al-Majmoo’ (3/122) and by al-Haafiz Ibn Hajar in al-Talkhees al-Habeer (1/211). 
The scholars of the Standing Committee for Issuing Fatwas said: 
The Sunnah is for the one who is listening to the iqaamah to say what the muezzin says, because it is a second adhaan. So you should respond as one responds to the adhaan. When the muezzin says Hayya ‘ala al-salaah, hayya ‘ala al-falaah (come to prayer, come to prosperity), the listener should say La hawla wa quwwata ila Billaah (there is no power and no strength except with Allah), and when he says Qad qaamat il-salaah (Prayer is about to begin), he should say the same, and he should not say Aqaamaha Allahu wa adaamaha (May Allah make is continually established), because the hadeeth concerning that is da’eef, and it is narrated in a saheeh hadeeth that the Messenger of Allah (peace and blessings of Allah be upon him) said: “When you hear the muezzin, say what he says.” This includes both the adhaan and the iqaamah, because both of them may be called adhaan. Then he should send blessings upon the Prophet (peace and blessings of Allah be upon him) after the muezzin says Laa ilaaha ill-Allah, and he should say: “Allahumma Rabba haadhihi’l-da’wat il-taammah wa’l-salaat il-qaa’imah, aati Muhammadan il waseelata wa’l-fadeelah, wab’athhu maqaaman mahmoodan illadhi wa’adtah (O Allah, Lord of this perfect call and the prayer to be offered, grant Muhammad the privilege (of intercession) and also the eminence, and resurrect him to the praised position that You have promised),” as he says after the adhaan. We do not know of any saheeh evidence to suggest that it is mustahabb to say any other du’aa’ between the end of the iqaamah and the opening takbeer of the prayer, apart from what has been mentioned. End quote. 
Shaykh ‘Abd al-‘Azeez Ibn Baaz, Shaykh ‘Abd al-Razzaaq ‘Afeefi, Shaykh ‘Abd-Allah ibn Qa’ood. 
Fatawa al-Lajnah al-Daa’imah (6/89, 90) 
And Allah knows best.