The Messenger of Allah ﷺ said, "The heaviest prayers for the hypocrites are the night prayer and Fajr. If they knew what reward lies in them, they would come to them even if they had to crawl."
إن أثقل الصلاة على المنافقين صلاة العشاء والفجر ولو يعلمون ما فيهما لأتوهما ولو حبوا