ὅστις

whoever, whatever; whosoever, whatsoever, Mt. 5:39, 41; 13:12; 18:4; its use in place of the simple relative is also required in various cases, which may be learned from the grammars; ἕως ὅτου, i.e. χρόνου, until, Lk. 13:8; while, Mt. 5:25