Hassan and Hashim narrated to us, they said: Shaiban narrated to us, from Asim, from Ziyad ibn Qays, from Abu Huraira, from the Prophet, peace and blessings be upon him, who said: "Woe to the Arabs from an evil that has drawn near; knowledge will decrease, and al-harj will increase." He said: I said, "O Messenger of Allah, what is al-harj?" He said: "Killing."
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 10984