the scouting body of madinah reported that banu saleem of ghatafan were engaged in mustering troops to invade the muslims. the prophet [pbuh] took the initiative himself and mounted a surprise attack on them in their own homeland at a watering place called al-kudr. banu saleem, on receiving the news, had fled before he arrived. he stayed there for three days, took their 500 camels as booty and distributed them to the fighters after he had set aside the usual one-fifth; each one gained two camels.
this invasion took place in shawwal in the year 2 a.h., seven days after the event of badr.[za'd al-ma'ad 2/90; ibn hisham 2/43,44; mukhtasar seerat ar-rasool p.236]