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.
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

See similar narrations below:

Collected by Ibn Mājah
ibnmajah:200Abū 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:٢٠٠حَدَّثَنَا 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