Reference: Fataawa tata’allaq bi-Jamaa’ah al-Masjid – Question 26, Page 26
Liqaa. al-Baab al-Maftooh – Volume 55, Page 124
Question: Noble Shaykh, we hear some people say «أقامها الله و أدامها» after the iqaamah for the prayer [is called]. What is the ruling regarding this?
Response: It has been mentioned in a hadeeth of the Messenger (sal-Allaahu ‘alayhi wa sallam) that when the mu.adhdhin calls the iqaamah and says «قد قامت الصلاة» that he (the Prophet) used to say «أقامها الله و أدامها». However, this hadeeth is weak and is not sufficient proof [for this action].