Allah's Messenger (ﷺ) said, "Whilst a shepherd was amongst his sheep, a wolf attacked them and took away
a sheep. The shepherd chased it and got that sheep freed from the wolf. The wolf turned towards the
shepherd and said, 'Who will guard the sheep on the day of wild animals when it will have no
shepherd except myself?" The people said, "Glorified be Allah." The Prophet (ﷺ) said, "But I believe in it
and so do Abu Bakr and `Umar although Abu Bakr and `Umar were not present there (at the place of
the event).
Sahih al-Bukhari Book 62, Hadith 40