Mishkat al-Masabih

‘Abdallah b. as-Sa’ib said God’s Messenger used to pray four rak'as before the noon prayer, after the sun had passed the meridian, saying, “It is an hour at which the gates of heaven are opened, and I like a good deed of mine to ascend at that time.” Tirmidhi transmitted it.

وَعَنْ عَبْدِ اللَّهِ بْنِ السَّائِبِ قَالَ: كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسلم يُصَلِّي أَرْبَعًا بَعْدَ أَنْ تَزُولَ الشَّمْسُ قَبْلَ الظُّهْرِ وَقَالَ: «إِنَّهَا سَاعَةٌ تُفْتَحُ فِيهَا أَبْوَابُ السَّمَاءِ فَأُحِبُّ أَنْ يَصْعَدَ لِي فِيهَا عَمَلٌ صَالِحٌ» . رَوَاهُ التِّرْمِذِيّ