صحیح مسلم · Hadith 2141

Anas b. Malik reported that Allah's Messenger ( ‌صلی ‌اللہ ‌علیہ ‌وسلم ‌ ) came to a woman who had been weeping for her (dead) child, and said to her: Fear Allah and show endurance. She (not recognising him) said: You have not been afflicted as I have been. When he (the Holy Prophet) had departed, it was said to her that he was the Messenger of Allah ( ‌صلی ‌اللہ ‌علیہ ‌وسلم ‌ ), she was mortally shocked. She came to his door and she did not find doorkeepers at his door. She said: Messenger of Allah. I did not recognise you. He said: Endurance is to be shown at first blow, or at the first blow.