Qayam ul Layl Abu Huraira reported: The Messenger of Allah(‎ﷺ), peace and blessings be upon him, encouraged standing for night prayer in the month of Ramadan, without imposing it on them. The Prophet would say:

Whoever stands in prayer during Ramadan due to faith and seeking reward, his previous sins will be forgiven.

Ṣaḥīḥ al-Bukhārī 2009″