Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
ibnmajah:200 – Abū Kurayb Muḥammad b. al-ʿAlāʾ > ʿAbdullāh b. Ismāʿīl > Mujālid > Abū al-Waddāk > Abū Saʿīd al-Khudrī

"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.'"  

ابن ماجة:٢٠٠ – حَدَّثَنَا أَبُو كُرَيْبٍ مُحَمَّدُ بْنُ الْعَلاَءِ حَدَّثَنَا عَبْدُ اللَّهِ بْنُ إِسْمَاعِيلَ عَنْ مُجَالِدٍ عَنْ أَبِي الْوَدَّاكِ عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ قَالَ

قَالَ رَسُولُ اللَّهِ ﷺ إِنَّ اللَّهَ لَيَضْحَكُ إِلَى ثَلاَثَةٍ لِلصَّفِّ فِي الصَّلاَةِ وَلِلرَّجُلِ يُصَلِّي فِي جَوْفِ اللَّيْلِ وَلِلرَّجُلِ يُقَاتِلُ أُرَاهُ قَالَ خَلْفَ الْكَتِيبَةِ  

See similar narrations below:

Collected by Suyūṭī
suyuti:5015a –

"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.'" (Using translation from Ibn Mājah 200)   

السيوطي:٥٠١٥a –

"إِنَّ الله لَيَضْحَكُ إِلَى ثَلاثة: الصَّف فِي الصَّلَاةِ؛ والرَّجُل يُصَلِّي في جَوْفِ الليلِ، ولِلرَّجُلِ يُقَاتِلُ خَلْفَ الْكَتِيبة".  

[هـ] ابن ماجة عن أَبي سعيد