DARIMI 1305:
from Ubay b. Kaʿb —
[Machine] The Messenger of Allah ﷺ prayed the Fajr prayer, then he turned towards us and said, "Is [so and so] present?" They replied, "No." He then asked, "Is [so and so] present?" They replied, "No." He asked this about some hypocrites who did not attend the prayer. He then said, "Indeed, these two prayers are the heaviest on the hypocrites. If they knew their reward, they would have surely come to them even if they had to crawl."
الدارمي ١٣٠٥:
عن ابي بن كعب —
صَلَّى رَسُولُ اللَّهِ ﷺ صَلَاةَ الصُّبْحِ ثُمَّ أَقْبَلَ عَلَيْنَا بِوَجْهِهِ فَقَالَ «أَشَاهِدٌ فُلَانٌ؟» قَالُوا لَا فَقَالَ «أَشَاهِدٌ فُلَانٌ؟» فَقَالُوا لَا لِنَفَرٍ مِنَ الْمُنَافِقِينَ لَمْ يَشْهَدُوا الصَّلَاةَ فَقَالَ «إِنَّ هَاتَيْنِ الصَّلَاتَيْنِ أَثْقَلُ الصَّلَاةِ عَلَى الْمُنَافِقِينَ وَلَوْ يَعْلَمُونَ مَا فِيهِمَا لَأَتَوْهُمَا وَلَوْ حَبْوًا»
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