Musnad Ahmad 110
It was narrated that Ibn ‘Abbas said:
Some men of good character, among whom was ‘Umar, testified before me, and the best of them in my view was ‘Umar, that the Prophet of Allah ﷺ used to say: `There is no prayer after 'Asr prayer until the sun sets, and there is no prayer after Fajr prayer until the sun rises.`
حَدَّثَنَا بَهْزٌ، حَدَّثَنَا أَبَانُ، عَنْ قَتَادَةَ، عَنْ أَبِي الْعَالِيَةِ، عَنِ ابْنِ عَبَّاسٍ، قَالَ شَهِدَ عِنْدِي رِجَالٌ مَرْضِيُّونَ مِنْهُمْ عُمَرُ وَأَرْضَاهُمْ عِنْدِي عُمَرُ أَنَّ نَبِيَّ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ كَانَ يَقُولُ لَا صَلَاةَ بَعْدَ صَلَاةِ الْعَصْرِ حَتَّى تَغْرُبَ الشَّمْسُ وَلَا صَلَاةَ بَعْدَ صَلَاةِ الصُّبْحِ حَتَّى تَطْلُعَ الشَّمْسُ‏.‏