Jihad (Kitab Al-Jihad)
Dawud :: Book 14 : Hadith 2745
Narrated Abdullah ibn Amr ibn al-'As:
The Apostle of Allah (peace_be_upon_him) said: Muslims are equal in respect of blood. The lowest of them is entitled to give protection on behalf of them, and the one residing far away may give protection on behalf of them. They are like one hand over against all those who are outside the community. Those who have quick mounts should return to those who have slow mounts, and those who got out along with a detachment (should return) to those who are stationed. A believer shall not be killed for an unbeliever, nor a confederate within the term of confederation with him.