It is narrated from Sayyiduna Bishr bin Suhaim (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: "Constantinople will certainly be conquered; its commander will be the best commander and that army will be the best army." Abdullah says: Maslamah bin Abdul Malik called me and asked me about this, so I narrated this hadith to him, and because of this, he launched an expedition against Constantinople.