Sahih Muslim 1809 a, b
It has been narrated on the authority of Anas that, on the Day of Hunain. Umm Sulaim took out a dagger she had in her possession. Abiu Talha saw her and said:
Messenger of Allah, this is Umm Sulaim. She is holding a dagger. The Messenger of Allah (ﷺ) asked (her): What for are you holding this dagger? She said: I took it up so that I may tear open the belly of a polytheist who comes near me. The Messenger of Allah (ﷺ) began to smile (at these words). She said: Messenger of Allah, kill all those people-other than us-whom thou hast declared to be free (on the day of the Conquest of Mecca). (They embraced Islam because) they were defeated at your hands (and as such their Islam is not dependable). The Messenger of Allah (ﷺ) said: Umm Sulaim. God is sufficient (against the mischief of the polytheists) and He will be kind to us (so you need not carry this dagger).
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا يَزِيدُ بْنُ هَارُونَ، أَخْبَرَنَا حَمَّادُ بْنُ سَلَمَةَ، عَنْ ثَابِتٍ، عَنْ أَنَسٍ، أَنَّ أُمَّ سُلَيْمٍ، اتَّخَذَتْ يَوْمَ حُنَيْنٍ خِنْجَرًا فَكَانَ مَعَهَا فَرَآهَا أَبُو طَلْحَةَ فَقَالَ يَا رَسُولَ اللَّهِ هَذِهِ أُمُّ سُلَيْمٍ مَعَهَا خَنْجَرٌ فَقَالَ لَهَا رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ مَا هَذَا الْخَنْجَرُ ‏"‏ ‏.‏ قَالَتِ اتَّخَذْتُهُ إِنْ دَنَا مِنِّي أَحَدٌ مِنَ الْمُشْرِكِينَ بَقَرْتُ بِهِ بَطْنَهُ ‏.‏ فَجَعَلَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَضْحَكُ قَالَتْ يَا رَسُولَ اللَّهِ اقْتُلْ مَنْ بَعْدَنَا مِنَ الطُّلَقَاءِ انْهَزَمُوا بِكَ ‏.‏ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ يَا أُمَّ سُلَيْمٍ إِنَّ اللَّهَ قَدْ كَفَى وَأَحْسَنَ ‏"‏ ‏.‏
 وَحَدَّثَنِيهِ مُحَمَّدُ بْنُ حَاتِمٍ، حَدَّثَنَا بَهْزٌ، حَدَّثَنَا حَمَّادُ بْنُ سَلَمَةَ، أَخْبَرَنَا إِسْحَاقُ بْنُ، عَبْدِ اللَّهِ بْنِ أَبِي طَلْحَةَ عَنْ أَنَسِ بْنِ مَالِكٍ، فِي قِصَّةِ أُمِّ سُلَيْمٍ عَنِ النَّبِيِّ صلى الله عليه وسلم مِثْلَ حَدِيثِ ثَابِتٍ ‏.‏