(2) باب مَنْ سُئِلَ عِلْمًا وَهُوَ مُشْتَغِلٌ فِي حَدِيثِهِ فَأَتَمَّ الْحَدِيثَ ثُمَّ أَجَابَ السَّائِلَ
Narrated Abu Huraira:
While the Prophet (ﷺ) was saying something in a gathering, a Bedouin came and asked him, "When would the Hour (Doomsday) take place?" Allah's Messenger (ﷺ) continued his talk, so some people said that Allah's Messenger (ﷺ) had heard the question, but did not like what that Bedouin had asked. Some of them said that Allah's Messenger (ﷺ) had not heard it. When the Prophet (ﷺ) finished his speech, he said, "Where is the questioner, who inquired about the Hour (Doomsday)?" The Bedouin said, "I am here, O Allah's Apostle ." Then the Prophet (ﷺ) said, "When honesty is lost, then wait for the Hour (Doomsday)." The Bedouin said, "How will that be lost?" The Prophet (ﷺ) said, "When the power or authority comes in the hands of unfit persons, then wait for the Hour (Doomsday.)"
Reference: Sahih al-Bukhari 59
In-book reference: Book 3, Hadith 1
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 1, Book 3, Hadith 56