Anas bin Malik reported,

The Messenger of Allah ﷺ set out one day on one of his journeys, accompanied by a number of his companions. As they traveled along, the time for prayer arrived, but the people could find no water for their wudu.They said, "Messenger of Allah, by Allah, we can find nothing to perform wudu with."He saw the distress of this on his companions' faces. Then one of the men went off and came back with a cup holding only a little water. The Prophet of Allah ﷺ took it and performed his wudu from it, then stretched his four fingers over the cup and said, "Come, perform your wudu."So the people performed wudu, and they had all the water they needed.Someone asked how many of them there were. He replied, "Seventy, or thereabouts."

حدثنا يونس حدثنا حزم قال سمعت الحسن يقول

حدثنا أنس بن مالك

أن رسول الله ﷺ خرج ذات يوم لبعض مخارجه ومعه ناس من أصحابه فانطلقوا يسيرون فحضرت الصلاة فلم يجد القوم ماء يتوضئون به فقالوا يا رسول الله والله ما نجد ما نتوضأ به ورأى في وجوه أصحابه كراهية ذلك فانطلق رجل من القوم فجاء بقدح من ماء يسير فأخذ نبي الله ﷺ فتوضأ منه ثم مد أصابعه الأربعة على القدح ثم قال هلموا فتوضئوا فتوضأ القوم حتى أبلغوا فيما يريدون قال سئل كم بلغوا قال سبعين أو نحو ذلك