the Messenger of Allah used to encourage the people to pray Qiyam in Ramadan, without insisting on that. He said: "Whoever spends the nights of Ramadan in prayer out of faith and in the hope of reward, he will be forgiven his previous sins." ' (Using translation from Nasāʾī 2192)
أَنَّ رَسُولَ اللهِ ﷺ كَانَ يَأْمُرُ بِقِيَامِ رَمَضَانَ مِنْ غَيْرِ أَنْ يَأْمُرَ فِيهِ بِعَزِيمَةٍ وَكَانَ يَقُولُ مَنْ قَامَ رَمَضَانَ إِيمَانًا وَاحْتِسَابًا غُفِرَ لَهُ مَا تَقَدَّمَ مِنْ ذَنْبِهِ