Hadithcore
Sunan Abi Dawud, 426
sahih· Al-Albani

Narrated Umm Farwah:

The Messenger of Allah (ﷺ) was asked: Which of the actions is best? He replied: Observing prayer early in its period. Al-Khuza'i narrated in his version from his aunt named Umm Farwah who took the oath of allegiance to the Prophet (ﷺ): He was questioned.

حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ الْخُزَاعِيُّ، وَعَبْدُ اللَّهِ بْنُ مَسْلَمَةَ، قَالاَ حَدَّثَنَا عَبْدُ اللَّهِ بْنُ عُمَرَ، عَنِ الْقَاسِمِ بْنِ غَنَّامٍ، عَنْ بَعْضِ، أُمَّهَاتِهِ عَنْ أُمِّ فَرْوَةَ، قَالَتْ سُئِلَ رَسُولُ اللَّهِ صلى الله عليه وسلم أَىُّ الأَعْمَالِ أَفْضَلُ قَالَ ‏

‏ الصَّلاَةُ فِي أَوَّلِ وَقْتِهَا ‏

‏ ‏.‏ قَالَ الْخُزَاعِيُّ فِي حَدِيثِهِ عَنْ عَمَّةٍ لَهُ يُقَالُ لَهَا أُمُّ فَرْوَةَ قَدْ بَايَعَتِ النَّبِيَّ صلى الله عليه وسلم أَنَّ النَّبِيَّ صلى الله عليه وسلم سُئِلَ ‏.‏

References2 variants
In-Book Reference
Book 2, Hadith 36
English Reference
Book 2, Hadith 426