Yahya bin Abdul-Rahman bin Hatib reported,

He performed umrah with Umar bin Khattab in a company that included Amr bin As. Umar bin Khattab stopped to rest at a point along the road near some water, and there he had a wet dream, with dawn nearly upon him. He found no water with the company, so he rode out until he reached the water and began washing whatever traces of the emission he could see, continuing until the light had spread.Amr bin As said to him, "Morning has come, and we have clothes with us. Leave your garment and let it be washed."Umar bin Khattab replied, "How astonishing you are, Amr bin As! Granted that you can find spare clothes, does everyone have spare clothes to find? By Allah, if I did that, it would become a sunnah. No, I will wash what I can see and sprinkle water over what I cannot see."

Malik 119

Sahih

و حدثني عن مالك عن هشام بن عروة عن أبيه

عن يحيى بن عبد الرحمن بن حاطب

أنه اعتمر مع عمر بن الخطاب في ركب فيهم عمرو بن العاص وأن عمر بن الخطاب عرس ببعض الطريق قريبا من بعض المياه فاحتلم عمر وقد كاد أن يصبح فلم يجد مع الركب ماء فركب حتى جاء الماء فجعل يغسل ما رأى من ذلك الاحتلام حتى أسفر فقال له عمرو بن العاص أصبحت ومعنا ثياب فدع ثوبك يغسل فقال عمر بن الخطاب واعجبا لك يا عمرو بن العاص لئن كنت تجد ثيابا أفكل الناس يجد ثيابا والله لو فعلتها لكانت سنة بل أغسل ما رأيت وأنضح ما لم أر

مالك 119صحيح
Contents
Reference
Commentary
Ayat
Collection
Muwatta Malik
Book
Purification
Numbering
Laithi 119
Malik 119