Allah's Messenger (S) said: "When the Iqamah has been called for the Salat then there is no Salat except the obligatory."
Jami` at-Tirmidhi Book 2, Hadith 274
← Previous Hadith Allah's Messenger (S) said: "When one of you prays the two Rak'ah of Fajr then let him lay down on his right (side)."

Jami` at-Tirmidhi Book 2, Hadith 273 Next Hadith → "Allah's Messenger (S) went out and the Iqamah was called for the Salat so I prayed As-Subh with him. Then the Prophet (S) turned and found me performing Salat so he said: 'Easy O Qais! Are there two prayers together?' I said: 'O Messenger of Allah! I did not perform the two Rak'ah (before) Fajr.' He said: 'Then there is no harm.'"

Jami` at-Tirmidhi Book 2, Hadith 275