أَخْبَرَنَا مُحَمَّدُ بْنُ إِبْرَاهِيمَ الْبَصْرِيُّ، عَنْ بِشْرٍ، - هُوَ ابْنُ الْمُفَضَّلِ - قَالَ حَدَّثَنَا شُعْبَةُ، عَنْ أَشْعَثَ بْنِ سُلَيْمٍ، عَنْ أَبِيهِ، عَنْ مَسْرُوقٍ، قَالَ قُلْتُ لِعَائِشَةَ أَىُّ الأَعْمَالِ أَحَبُّ إِلَى رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَتِ الدَّائِمُ ‏.‏ قُلْتُ فَأَىُّ اللَّيْلِ كَانَ يَقُومُ قَالَتْ إِذَا سَمِعَ الصَّارِخَ ‏.‏

It was narrated that Masruq said: "I said to 'Aishah: 'Which deed was most beloved to the Messenger of Allah (PBUH)?' She said: 'That which was done persistently.' I said: 'At what part of the night did he pray Qiyam?' She said: 'When he heard the rooster.'" Translation Not Available

Book Ref: Sunan An Nisai Book 20 Hadith 1616
Web Ref:  Sunan An Nisai Vol 2 Book 20 Hadith 1617