(14) باب اسْتِحْبَابِ رَكْعَتَيْ سُنَّةِ الْفَجْرِ وَالْحَثِّ عَلَيْهِمَا وَتَخْفِيفِهِمَا وَالْمُحَافَظَةِ عَلَيْهِمَا وَبَيَانِ مَا يُسْتَحَبُّ أَنْ يُقْرَأَ فِيهِمَا
Ibn 'Abbas reported that the Messenger of Allah (ﷺ) used to recite in the two (supererogatory) rak'ahs of the dawn prayer:
" Say: We believed in Allah and what was revealed to us" and that which is found in Surah Al-i-'lmran:" Come to that word (creed) which is common between you and us" (iii. 64).
Reference: Sahih Muslim 727 b
In-book reference: Book 6, Hadith 122
USC-MSA web (English) reference(deprecated numbering scheme): Book 4, Hadith 1577