سنن ابن ماجه

It was narrated that ‘Aishah said: “The Messenger of Allah (ﷺ) went out delighted, then he came back to me sad. I said: ‘O Messenger of Allah, (why did) you go out happy and come back sad?’ He said: ‘I entered the Ka’bah, and I wish that I had not done that, because I am afraid that I may have caused difficulty for my nation after I am gone.’”