You have today done something that you have not been accustomed to before. He (the Holy Prophet) said: 0 'Umar, I have done that on purpose.
Sahih Muslim Book 2, Hadith 108
← Previous Hadith I asked 'A'isha about wiping over the shoes. She said: You better go to 'Ali, for he knows more about this than I. I, therefore, came to 'Ali and he narrated from the Apostle (ﷺ) like this.

Sahih Muslim Book 2, Hadith 107 Next Hadith → 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.

Sahih Muslim Book 2, Hadith 109