No Salaat (prayer) is more heavy (harder) for the hypocrites than the Fajr and the ‘Ishaa prayers

Bismillaah, wal-hamdulilaah, was-salaatu was-salaamu ‘alaa rasoolillaah,
as Salaamu ‘Alaykum wa Rahmatullaahi wa Barakaatuh

383. Narrated Aboo Huraira (radhi Allaahu anhu) :- The Prophet (Sallallaahu Alaihi Wasallam) said,

“No Salaat (prayer) is more heavy (harder) for the hypocrites than the Fajr and the ‘Ishaa prayers, and if they knew the reward for these Salaat (prayers) at their respective times, they would certainly present themselves (in the mosques) even if they had to crawl.” The Prophet (Sallallaahu Alaihi Wasallam) added, “Certainly, I intended or planned or decided to order the Mu’adhdhin (call-maker) to pronounce Iqaama and then take a fire flame to burn all those (men along with their houses who had not left their houses) so far for As-Salaat (the prayer) (in the mosque).”

[Saheeh Al-Bukhaari, Hadeeth No. 626, Vol. 1]

Source :The Book of Mosques and places of worship – Chapter 42 – Superiority of obligatory Salaat (prayer) in congregation and severe warning to those who keep away from it. Al-Lulu Wal-Marjan, Compiled by : Fuwad Abdul-Baqi, Translated by : Dr. Muhammad Muhsin Khan

Urging to Observe ‘Isha’ and Fajr Prayers in Congregation – Riyadh ul saaliheen