The Book of Prayer
Bulugh al-Maram #213
كتاب الصلاة
وَلِابْنِ خُزَيْمَةَ: عَنْ أَنَسٍ قَالَ: «مِنْ اَلسُّنَّةِ إِذَا قَالَ اَلْمُؤَذِّنُ فِي اَلْفَجْرِ: حَيٌّ عَلَى اَلْفَلَاحِ, قَالَ: اَلصَّلَاةُ خَيْرٌ مِنَ اَلنَّوْمِ»
Ibn Khuzaimah reported from Anas (RA):
“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).'”
وَلِابْنِ خُزَيْمَةَ: عَنْ أَنَسٍ قَالَ: "مِنْ اَلسُّنَّةِ إِذَا قَالَ اَلْمُؤَذِّنُ فِي اَلْفَجْرِ: حَيٌّ عَلَى اَلْفَلَاحِ, قَالَ: اَلصَّلَاةُ خَيْرٌ مِنَ اَلنَّوْمِ"
"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).'"
— Bulugh al-Maram, Hadith 213