The most burdensome prayers for the hypocrites are the ‘Ishā and Fajr prayers. If they were to know the virtue of them, they would come to them even if they had to crawl. [Al-Bukhari]
أَثقَل الصَّلاةِ على المُنَافِقِين: صَلاَة العِشَاء، وصَلاَة الفَجر، وَلَو يَعلَمُون مَا فِيها لَأَتَوهُمَا وَلَو حَبْوُا (البخاري)