Zuhr is named for what it is, the time when the sun has passed its zenith. Asr was prayed while the sun was still bright and full of life. Maghrib is named for what it is, the time of sunset. We used to pray Maghrib with the Messenger of Allah ﷺ and then return to our homes about a mile away, and we could still see where our arrows landed. He would sometimes hasten Isha and sometimes delay it. And Fajr is named for what it is, and he used to pray it while it was still dark.
حدثنا وكيع عن سفيان عن عبد الله بن محمد بن عقيل
الظهر كاسمها والعصر بيضاء حية والمغرب كاسمها وكنا نصلي مع رسول الله ﷺ المغرب ثم نأتي منازلنا وهي على قدر ميل فنرى مواقع النبل وكان يعجل العشاء ويؤخر والفجر كاسمها وكان يغلس بها