When dawn broke, the Prophet ﷺ would pray two rakahs.
كان النبي ﷺ إذا أضاء الفجر صلى ركعتين.
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Muslim narrated it in the chapter on the prayer of travelers (723:89), from Muhammad bin Abbad, Sufyan narrated to us, from Amr, from Zuhri, from Salim, from his father, who said, "Hafsa informed me," and he mentioned the hadith. In another narration, from Zayd bin Muhammad, who said, "I heard Nafi narrating from Ibn Umar, from her, that she said, 'When Fajr rises, he would not pray except two light rakahs.'"Ibn Majah narrated it (1143) from Hisham bin Ammar, who said, "Sufyan bin Uyayna narrated to us, from Amr bin Dinar, from Ibn Umar, that the Prophet ﷺ would pray two rakahs whenever dawn became clear to him."The apparent chain is sahih, except that the preserved version is from Ibn Umar, from Hafsa, as mentioned earlier.