When anyone amongst you wakes up from sleep, he must not put his hand in the utensil till he has washed it three times, for he does not know where his hand was during the night
Allah’s Messenger (ﷺ) said, “If anyone of you performs ablution he should put water in his nose and then blow it out and whoever cleans his private parts with stones should do so with odd numbers. And whoever wakes up from his sleep should wash his hands before putting them in the water for ablution, because nobody knows where his hands were during sleep.”
Abu Hurairah reported :
The Messenger of Allah (ﷺ) said: When anyone amongst you wakes up from sleep at night, he should not put his hand in the utensil until he has washed his hand three times, for he does’ not know where his hand was during the night.
Sunan Abu Dawood