The Prophet ﷺ said, "May Allah have mercy on a person who prays four units before the Asr prayer."
حدثنا يحيى بن موسى ومحمود بن غيلان وأحمد بن إبراهيم الدورقي وغير واحد قالوا حدثنا أبو داود الطيالسي حدثنا محمد بن مسلم بن مهران سمع جده
عن النبي ﷺ قال رحم الله امرأ صلى قبل العصر أربعا
Its isnad is hasan. Abu Dawud narrated it in the Book of Voluntary Prayers, the chapter on prayer before Asr, hadith no. 1271, from Ibn Ibrahim Dawraqi with this wording, and graded it sahih. Ibn Khuzayma also narrated it, hadith no. 1193, as did Ibn Hibban, hadith no. 616, and others.In the Musnad of Abu Dawud Tayalisi, hadith no. 1936, and from his route Bayhaqi, 2/473, it appears as, "Abu Dawud said, Muhammad bin Muthanna narrated to us from his father from his grandfather," which is an error.