It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that when the Prophet (peace and blessings be upon him) was expelled from Makkah Mukarramah, Sayyiduna Abu Bakr Siddiq (may Allah be pleased with him) began to say with sorrow: "These people have expelled their Prophet," and he began to recite "Inna lillahi," and said, "They will surely be destroyed." Upon this, the verse was revealed: "Permission [to fight] is given to those against whom fighting is waged, because they have been wronged, and indeed Allah is able to help them." At that moment, he understood that now fighting would certainly take place. Sayyiduna Ibn Abbas (may Allah be pleased with them both) says that this is the very first verse regarding the permission to fight.