It is narrated from a Companion of the Prophet, Sayyiduna Dhi Mikhmar (may Allah be pleased with him), that the Messenger of Allah (peace and blessings be upon him) said: "Soon the Romans will make a peace treaty with you in safety. Then you and they will together fight a common enemy. You will be helped, you will remain safe, and you will obtain spoils of war. But when you camp at a place with green, grassy hills, at that time a Christian man will raise the cross and say, 'The cross has prevailed.' Hearing this, a Muslim will be stirred by zeal and will get up and break that cross. At this point, the Romans will break their treaty with you and will gather for a fierce battle."