His father reported, "The Messenger of Allah ﷺ taught me, and among the things he taught me was, 'Maintain the five prayers.'"He said, "I replied, 'These are times when I am occupied with various tasks. Give me a comprehensive instruction that, if I act upon it, will suffice for me.'"He said, "Maintain the two Asrs."This expression was not part of our dialect, so I asked, "What are the two Asrs?"He replied, "A prayer before sunrise and a prayer before sunset."
حدثنا عمرو بن عون أخبرنا خالد عن داود بن أبي هند عن أبي حرب بن أبي الأسود
عن أبيه قال علمني رسول الله ﷺ فكان فيما علمني وحافظ على الصلوات الخمس قال قلت إن هذه ساعات لي فيها أشغال فمرني بأمر جامع إذا أنا فعلته أجزأ عني فقال حافظ على العصرين وما كانت من لغتنا فقلت وما العصران فقال صلاة قبل طلوع الشمس وصلاة قبل غروبها
[Its isnad is sahih, and Ibn Hibban graded it sahih, no. 282, and Hakim (20/1 and 628/3), and Dhahabi agreed with him. The hadith should be understood in relation to congregation, meaning that he was given permission to miss attending some of the prayers in congregation, not to abandon it altogether. Understand this well, for it is important. The hadith has another version with Ahmad (344/4), and this does not cause any harm, praise be to Allah.