Sahih Muslim 1254 b
It has been narrated on the authority of Abu Ishaq that 'Abdullah b. Yazid went (out of the city) with people for offering" Istisqa" ' prayer (for rainfall). He offered two rak'ahs. Then he prayed for rain. That day I met Zaid b. Arqam. There was only one man between me and him (at that time). I asked him:
How many military expeditions did the Messenger of Allah (ﷺ) undertake? He said: Nineteen expeditions. I asked him: On how many expeditions did you accompany him? He said: On seventeen expeditions. I asked: Which was the first expedition he led? He answered: Dhat-ul-, Usair or 'Ushair.
حَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، وَابْنُ، بَشَّارٍ - وَاللَّفْظُ لاِبْنِ الْمُثَنَّى - قَالاَ حَدَّثَنَا مُحَمَّدُ، بْنُ جَعْفَرٍ حَدَّثَنَا شُعْبَةُ، عَنْ أَبِي إِسْحَاقَ، أَنَّ عَبْدَ اللَّهِ بْنَ يَزِيدَ، خَرَجَ يَسْتَسْقِي بِالنَّاسِ فَصَلَّى رَكْعَتَيْنِ ثُمَّ اسْتَسْقَى قَالَ فَلَقِيتُ يَوْمَئِذٍ زَيْدَ بْنَ أَرْقَمَ - وَقَالَ - لَيْسَ بَيْنِي وَبَيْنَهُ غَيْرُ رَجُلٍ أَوْ بَيْنِي وَبَيْنَهُ رَجُلٌ - قَالَ - فَقُلْتُ لَهُ كَمْ غَزَا رَسُولُ اللَّهِ صلى الله عليه وسلم قَالَ تِسْعَ عَشْرَةَ فَقُلْتُ كَمْ غَزَوْتَ أَنْتَ مَعَهُ قَالَ سَبْعَ عَشْرَةَ غَزْوَةً - قَالَ - فَقُلْتُ فَمَا أَوَّلُ غَزْوَةٍ غَزَاهَا قَالَ ذَاتُ الْعُسَيْرِ أَوِ الْعُشَيْرِ ‏.‏