Sahih Bukhari

Ṣaḥīḥ al-Bukhārī (Arabic: صحيح البخاري‎‎) is one of the Kutub al-Sittah (six major hadith collections) of Sunni Islam. These prophetic traditions, or hadith, were collected by the Persian Muslim scholar Muhammad al-Bukhari, after being transmitted orally for generations. Sunni Muslims view this as one of the two most trusted collections of hadith along with Sahih Muslim. It is also used as an authentic hadith collection by Zaidi Shia Muslims. In some circles, it is considered the most authentic book after the Quran.The Arabic word sahih translates as authentic or correct.

One of it's content:

Narrated by Abu Huraira,

While the Prophet was saying something in a gathering, a Bedouin came and asked him, "When would the Hour (Doomsday) take place?" Allah's Apostle continued his talk, so some people said that Allah's Apostle had heard the question, but did not like what that Bedouin had asked. Some of them said that Allah's Apostle had not heard it. When the Prophet 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 said, "When honesty is lost, then wait for the Hour (Doomsday)." The Bedouin said, "How will that be lost?" The Prophet said, "When the power or authority comes in the hands of unfit persons, then wait for the Hour (Doomsday.)"