صَحِيحُ مُسْلِمٍ
Sahih Muslim 1769 b
The Book of Jihad and Expeditions
Permissibility of fighting those who break a treaty; Permissibility of letting besieged people surrender, subject to the judgement of a just person who is qualified to pass judgement
وَحَدَّثَنَا أَبُو كُرَيْبٍ، حَدَّثَنَا ابْنُ نُمَيْرٍ، حَدَّثَنَا هِشَامٌ، قَالَ قَالَ أَبِي فَأُخْبِرْتُ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ لَقَدْ حَكَمْتَ فِيهِمْ بِحُكْمِ اللَّهِ عَزَّ وَجَلَّ .
It has been narrated on the authority of Hisham (who learnt it from his father) that the Messenger of Allah (ﷺ) said (to Sa'd): You have adjudged their case with the judgment of God. the Exalted and Glorified.
Sahih Muslim, 1769 bSahihصحيح