"The Messenger of Allah ﷺ aid: 'When the Iqamah for prayer is said, there is no prayer except the prescribed prayer."'  

قَالَ رَسُولُ اللَّهِ ﷺ إِذَا أُقِيمَتِ الصَّلاَةُ فَلاَ صَلاَةَ إِلاَّ الْمَكْتُوبَةُ  

"When the Iqamah for prayer is said, there is no prayer except the prescribed prayer."  

عَنِ النَّبِيِّ ﷺ قَالَ إِذَا أُقِيمَتِ الصَّلاَةُ فَلاَ صَلاَةَ إِلاَّ الْمَكْتُوبَةُ  

"The Iqamah for Subh prayer was said, and the Messenger of Allah ﷺ saw a man praying while the Mu'adhdhin saying the Iqamah. He said: 'Are you praying Subh with four Rak'ahs?"'  

أُقِيمَتْ صَلاَةُ الصُّبْحِ فَرَأَى رَسُولُ اللَّهِ ﷺ رَجُلاً يُصَلِّي وَالْمُؤَذِّنُ يُقِيمُ فَقَالَ أَتُصَلِّي الصُّبْحَ أَرْبَعًا