The Messenger of Allah ﷺ said, "The most burdensome prayers for the hypocrites are the Isha prayer and the Fajr prayer. If they only knew what reward lies in them, they would come to them even if they had to crawl."
حدثنا أبو بكر بن أبي شيبة أنبأنا أبو معاوية عن الأعمش عن أبي صالح
قال رسول الله ﷺ إن أثقل الصلاة على المنافقين صلاة العشاء وصلاة الفجر ولو يعلمون ما فيهما لأتوهما ولو حبوا
Muslim narrated it in Al-Masajid, chapter on the virtue of congregational prayer and the emphasis regarding it, etc., hadith no. 651, from the hadith of Abu Muawiya, with this wording.