Narrated Sa’īd bin Jubair: ‘Abdullāh bin ‘Umar came to us and we hoped that he would narrate to us a good Hadīth. But before we asked him, a man got up and said to him, “O abu ‘Abdur-Rahmān! Narrate to us about the battles during the time of Al-Fitnah (trial and affliction) as Allāh says:
‘And fight them until there is no more Fitnah (i.e. no more disbelief and worshipping of others along with Allāh, trial and afflictions).’ [2:193]”
Ibn ‘Umar said (to the man), “Do you know what is meant by Al-Fitnah? Let your mother bereave you! Muhammad salAllāhu ‘alayhi wa salam used to fight against Al-Mushrikun, for a Muslim was put to trial in his religion (Al-Mushrikun will either kill him or chain him as a captive). His fighting was not like your fighting which is carried on for the sake of ruling.”
Source: Sahīh al-Bukhārī, 92 – The Book of Al-Fitan, (16) Chapter. The statement of the Prophet salAllāhu ‘alayhi wa salam: “Al-Fitnah (trial and affliction) will appear from the east.”, 9/142, darussalam.