When the highway robbers form a group (1), one of them may personally carry out the killing while the others aid and support him. It has been said that only the direct perpetrator is to be executed. The majority, however, hold that all of them are to be executed, even if they number one hundred, and that the supporter and the direct perpetrator are treated alike. This is the position transmitted from (2) the Rightly Guided Caliphs: Umar ibn al-Khattab, may Allah be pleased with him, executed the highway robbers’ lookout (3). A lookout is one who keeps watch (4), sitting at an elevated place to see who may be approaching them. This is because the direct perpetrator was able to carry out the killing only through the strength and assistance provided by those supporting him.
When the members of a group reinforce one another until they become a force capable of resistance, they share in reward and punishment, as do those who fight in jihad. The Prophet, may Allah bless him and grant him peace, said: “The lives of Muslims are of equal worth; even the least of them may grant protection binding upon them all; they are united against all others; and those who go forth in a detachment share their gains with those who remain behind” (5).
This means that if a detachment goes forth from the Muslim army (6) and captures some property as spoils, then