أَخْبَرَنَا إِبْرَاهِيمُ بْنُ هَارُونَ، قَالَ حَدَّثَنَا حَاتِمُ بْنُ إِسْمَاعِيلَ، قَالَ حَدَّثَنَا جَعْفَرُ بْنُ مُحَمَّدِ بْنِ عَلِيِّ بْنِ الْحُسَيْنِ، عَنْ أَبِيهِ، أَنَّ جَابِرَ بْنَ عَبْدِ اللَّهِ، قَالَ صَلَّى رَسُولُ اللَّهِ صلى الله عليه وسلم الصُّبْحَ حِينَ تَبَيَّنَ لَهُ الصُّبْحُ ‏.‏

Ja'far bin Muhammad bin 'Ali bin Al-Husain narrated from his father, that Jabir bin 'Abdullah said: "The Messenger of Allah (PBUH) prayed Subh as soon as he was certain the dawn had appeared." Translation Not Available

Book Ref: Sunan An Nisai Book 6 Hadith 548
Web Ref:  Sunan An Nisai Vol 1 Book 6 Hadith 544