Öz:Muslims have started to move forward to Iraq and Syria regions quickly with The First Islamic Conquests after the death of the Prophet Mohammed. In fact, Muslims who had conquered many other fortified cities like Jerusalem had to put of the conquest of this city due to their respect for the sanctity of the city and their desire to seize the city without shedding anymore blood and destroying it. This idea is supported by the fact that, although Muslims have the position to conquer Aelia with less effort and the superiority of military, they have responded positively to the offer of Aelia people which requires Assurance of Safety given by Umar Ibn al- Khattab by himself and his positive response to it by reaching Jerusalem with difficulties after a month and giving them the wanted assurance and taking over the city with peace. The text which is written by Umar Ibn al-Khattab is not a treaty as thought but it is a one sided document given by him to People of Aelia. After all, Jerusalem which is sacred for Muslims, Christians and Jews was captured by without spilling blood and it is the beginning of a period with peace and trust for members of three divine religions.