Hadithcore
Hadith #2104400

Muslim has:

'He never prayed after the break of dawn except two light Rak'at.'

وَلِمُسْلِمٍ : { كَانَ إِذَا طَلَعَ اَلْفَجْرُ لَا يُصَلِّي إِلَّا رَكْعَتَيْنِ خَفِيفَتَيْنِ } [1]‏

References2 variants
Sunnah.com reference
Book 2, Hadith 256
Arabic/English book reference
Book 2, Hadith 348