"I came to the Messenger of Allah, who became Muslim with you?' He said: 'Free men and slaves.' I said: 'Is there any moment which brings one closer to Allah than another?' He said: 'Yes, the last part of the night, so pray as much as you want until you pray Subh, then stop until the sun has risen until and it looks like a shield and (its shinning)spreads. Then pray as much as you want until an object's shadow is at its shortest, then stop until the sun passes its zenith, for Hell is stoked at midday. Then pray 'Asr, then stop until you pray 'Asr, then stop until the sun has set, for it sets between the horns of a Shaitan and rises between the horns of a Shaitan.'" [1] [1] Similar has been recorded by Muslim. (Using translation from Nasāʾī 584)  

أَتَيْتُ رَسُولَ اللهِ ﷺ فَقُلْتُ يَا رَسُولَ اللهِ مَنْ أَسْلَمَ مَعَكَ؟ قَالَ حُرٌّ وَعَبْدٌ قَالَ قُلْتُ هَلْ مِنْ سَاعَةٍ أَقْرَبَ إِلَى اللهِ مِنْ أُخْرَى؟ قَالَ «نَعَمْ جَوْفُ اللَّيْلِ الْآخِرِ فَصَلِّ مَا بَدَا لَكَ حَتَّى تُصَلِّيَ الصُّبْحَ ثُمَّ انْتَهِ حَتَّى تَطْلُعَ الشَّمْسُ فَمَا دَامَتْ كَأَنَّهَا صَحْفَةٌ حَتَّى تَنْتَشِرَ ثُمَّ صَلِّ مَا بَدَا لَكَ حَتَّى يَقُومَ الْعَمُودُ عَلَى ظِلِّهِ ثُمَّ انْتَهِ حَتَّى تَزُولَ الشَّمْسُ فَإِنَّ جَهَنَّمَ تُسْجَرُ نِصْفَ النَّهَارِ ثُمَّ صَلِّ مَا بَدَا لَكَ حَتَّى تُصَلِّيَ الْعَصْرَ ثُمَّ انْتَهِ حَتَّى تَغْرُبَ الشَّمْسُ فَإِنَّهَا تَغْرُبُ بَيْنَ قَرْنَيْ شَيْطَانٍ وَتَطْلُعُ بَيْنَ قَرْنَيْ شَيْطَانٍ»