Musnad Al -Faruq, Commander of the Faithful, Abu Hafs Omar bin Al -Khattab, and his sayings on the gates of knowledge. Musnad Al -Faruq, Commander of the Faithful, Abu Hafs Omar bin Al -Khattab, and his sayings on the gates of knowledge. Musnad Al -Faruq, Commander of the Faithful, Abu Hafs Omar bin Al -Khattab, and his sayings on the gates of knowledge