Following this linguistic designation, came in the utterance of the Prophet - peace and blessings be upon him -: (Whenever a person is murdered unjustly, there is a share from the burden of the crime on the first son of Adam for he was the first to start “sanna” the tradition of murdering.) (11), meaning that Cain, the killer of Abel, gets a share in any shed blood; for he was first to start “sanna” killing, his saying: "the first to start “sanna” killing," implies that whoever starts “sanna” a matter, it is recorded for him or on him, and is a principle in the fact, which states that, aiding over that which is unlawful, is forbidden (12).
Thus, the Arab tribes designate he who started a matter, which is applied by a people after him, that it was him who initiated it “sannahu”.

(10) Lisaan-ul-‘Arab (13/225).
(11) Narrated by Bukhari in Kitab Al-Anbia’, section of the creation of Adam and his descendants, No (3335), and Muslim in Kitab Al-Qasamah, section of the pronouncement of the sin of he who instigated killing. No (1677).
(12) Complement of Fat? Al-Mulhim (2 / 213).