Salim bin Abdullah narrates from his father (Sayyiduna Abdullah bin Umar, may Allah be pleased with them both): The Prophet Muhammad (peace and blessings be upon him) said: "When any person wakes up from sleep, he should not put his hand into a vessel until he has washed it three times, for he does not know where his hand spent the night or what it touched during the night." A man said to Sayyiduna Abdullah bin Umar (may Allah be pleased with them both): What do you think? If that person wants to perform ablution from a pond (does he still have to do this)? So Ibn Umar (may Allah be pleased with them both) threw a pebble at him and said: "I am narrating to you a hadith from the Prophet Muhammad (peace and blessings be upon him), and you are saying, 'What do you think, if he wants to perform ablution from a pond?'" The chain of this narration is "Hasan" (good).