وَلِابْنِ خُزَيْمَةَ: عَنْ أَنَسٍ قَالَ: { مِنْ اَلسُّنَّةِ إِذَا قَالَ اَلْمُؤَذِّنُ فِي اَلْفَجْرِ: حَيٌّ عَلَى اَلْفَلَاحِ, قَالَ: اَلصَّلَاةُ خَيْرٌ مِنَ اَلنَّوْمِ } 1‏ .‏‏1 ‏- رواه ابن خزيمة (386)‏ بسند صحيح.‏

"It is from the Sunnah that when the Mu'adhadhin says Fajr (prayer time): 'Haiya 'alal-Falah (Come to the success)', he says (also) 'as-Salatu khairun minan-nawm (Prayer is better than sleep).'"