سُنَنُ ابْنِ مَاجَهْ
Sunan Ibn Majah 200
The Book of the Sunnah
Concerning what the Jahmiyyah denied (i.e., seeing Allah in the Hereafter, etc.)
حَدَّثَنَا أَبُو كُرَيْبٍ، مُحَمَّدُ بْنُ الْعَلاَءِ حَدَّثَنَا عَبْدُ اللَّهِ بْنُ إِسْمَاعِيلَ، عَنْ مُجَالِدٍ، عَنْ أَبِي الْوَدَّاكِ، عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ إِنَّ اللَّهَ لَيَضْحَكُ إِلَى ثَلاَثَةٍ لِلصَّفِّ فِي الصَّلاَةِ وَلِلرَّجُلِ يُصَلِّي فِي جَوْفِ اللَّيْلِ وَلِلرَّجُلِ يُقَاتِلُ - أُرَاهُ قَالَ - خَلْفَ الْكَتِيبَةِ .
It was narrated that Abu Sa'eed Al-Khudri said: "The Messenger of Allah said: 'Allah smiles at three things: a row in the prayer, a man who prays in the depths of the night, and a man who fights' I think he said, 'behind the battalion.'"
Sunan Ibn Majah, 200Da'if (Darussalam)