Reference: al-Muntaqaa min Fataawa Fadheelatush-Shaykh Saalih Ibn Fowzaan – Volume 2, Page 99, Fatwa No.82
Question: How correct is the hadeeth «The [Last] Hour shall not be established except upon the worst of the creation in the {sight] of Allaah»? And what does this [hadeeth] mean?
Response: This hadeeth is saheeh, and is narrated by al-Haakim in his Mustadrak, who says its chain of transmission is saheeh.
And the meaning of the hadeeth is clear, that at the end of time [close to] when the [Last] Hour shall be established, the souls of the believers (mu.minoon) shall be taken, as is mentioned in the hadeeth, and none shall remain except the disbelievers, and upon them shall the [Last] Hour be established.