بُلُوغُ الْمَرَامِ
Bulugh al-Maram 360
The Book of Prayer
وَعَنْ اِبْنِ عُمَرَ -رَضِيَ اَللَّهُ عَنْهُمَا- قَالَ : قَالَ رَسُولُ اَللَّهِ - صلى الله عليه وسلم -{ رَحِمَ اَللَّهُ اِمْرَأً صَلَّى أَرْبَعًا قَبْلَ اَلْعَصْرِ } رَوَاهُ أَحْمَدُ , وَأَبُو دَاوُدَ وَاَلتِّرْمِذِيُّ وَحَسَّنَهُ , وَابْنُ خُزَيْمَةَ وَصَحَّحَهُ . [1]
Narrated Ibn 'Umar (RA): Allah's Messenger (ﷺ) said: "May Allah mercy on a person who prays four Rak'at before the 'Asr prayer. " [Reported by Ahmad, Abu Da'ud and at-Tirmidhi and the latter graded it Hasan (good). Also reported by Ibn Khuzaimah who graded it Sahih (authentic)].
Sunnah.com reference: Book 2, Hadith 263