Anas b. Malik said (explaining the meaning of the Qur'anic verse "Who forsake their beds to cry unto their Lord in fear and hope, and spend of what We have bestowed on them" (32:16)). The people used to remain awake between the sunset and the night prayers and would pray. Al-Hasan used to say: (This verse means) the prayer and vigil at night.

حَدَّثَنَا أَبُو كَامِلٍ، حَدَّثَنَا يَزِيدُ بْنُ زُرَيْعٍ، حَدَّثَنَا سَعِيدٌ، عَنْ قَتَادَةَ، عَنْ أَنَسِ بْنِ مَالِكٍ، فِي هَذِهِ الآيَةِ { تَتَجَافَى جُنُوبُهُمْ عَنِ الْمَضَاجِعِ، يَدْعُونَ رَبَّهُمْ خَوْفًا وَطَمَعًا وَمِمَّا رَزَقْنَاهُمْ يُنْفِقُونَ } قَالَ : كَانُوا يَتَيَقَّظُونَ مَا بَيْنَ الْمَغْرِبِ وَالْعِشَاءِ يُصَلُّونَ، وَكَانَ الْحَسَنُ يَقُولُ : قِيَامُ اللَّيْلِ .