The Book on Salat (Prayer)
2/13. Chapter:
Virtue Of Performing Salat at the Beginning Of Its Prescribed Time
Jami at-Tirmidhi
حَدَّثَنَا أَبُو عَمَّارٍ الْحُسَيْنُ بْنُ حُرَيْثٍ، حَدَّثَنَا الْفَضْلُ بْنُ مُوسَى، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ الْعُمَرِيِّ، عَنِ الْقَاسِمِ بْنِ غَنَّامٍ، عَنْ عَمَّتِهِ أُمِّ فَرْوَةَ، وَكَانَتْ، مِمَّنْ بَايَعَتِ النَّبِيَّ صلى الله عليه وسلم قَالَتْ سُئِلَ النَّبِيُّ صلى الله عليه وسلم أَىُّ الأَعْمَالِ أَفْضَلُ قَالَ " الصَّلاَةُ لأَوَّلِ وَقْتِهَا " .
Umm Farwah - and she was one of those who gave pledge of allegiance to the Prophet - narrated: "The Prophet Was Asked: 'Which Deed Is The Best?' So He Said: 'Salat In The Beginning Of Its Time.'"
Reference : Jami` at-Tirmidhi 170In-book reference : Book 2, Hadith 22English translation : Vol. 1, Book 2, Hadith 170