A father is exiled as a result of his son, and a son is exiled as a result of his father. All are exiled as a result of an Israelite, and Israelites are exiled as a result of them, with the exception of a resident alien. A resident alien is exiled only as a result of a resident alien.  A blind person is not exiled; [these are] the words of R' Yehudah. R' Meir [however] says: He is exiled.  An enemy is not exiled. R' Yose bar Yehudah says: An enemy is executed because he is considered forewarned. R' Shimon says: Some enemies are exiled and some enemies are not exiled. This is the rule: Anyone concerning whom it can be said [that] he killed intentionally is not exiled; but [if it is clear] that he killed unintentionally, he is exiled.