Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
ahmad:13181al-Ḍaḥḥāk b. Makhlad > ʿAbd al-Raḥman b. And Rdān Madīnī

[Machine] Did you pray Asr (afternoon prayer)? They answered yes. We asked, "Tell us, may Allah rectify you, when did the Messenger of Allah ﷺ used to pray this prayer?" He said, "He used to pray it when the sun was pure white."  

أحمد:١٣١٨١حَدَّثَنَا الضَّحَّاكُ بْنُ مَخْلَدٍ حَدَّثَنَا عَبْدُ الرَّحْمَنِ بْنُ وَرْدَانَ مَدِينِيٌّ قَالَ دَخَلْنَا عَلَى أَنَسِ بْنِ مَالِكٍ فِي رَهْطٍ مِنْ أَهْلِ الْمَدِينَةِ قَالَ

صَلَّيْتُمْ يَعْنِي الْعَصْرَ ؟ قَالُوا نَعَمْ قُلْنَا أَخْبِرْنَا أَصْلَحَكَ اللهُ مَتَى كَانَ رَسُولُ اللهِ ﷺ يُصَلِّي هَذِهِ الصَّلَاةَ؟ قَالَ كَانَ يُصَلِّيهَا وَالشَّمْسُ بَيْضَاءُ نَقِيَّةٌ