The Art of War

probably more than merely 居止 or 稽留 “detain.”  Cf.  infra (“The end and aim of spying⁠ ⁠…”), where Sun Tzǔ insists that these converted spies shall be treated well. Chang Yü’s paraphrase is 館舍.  ↩

Tu Yu expands 因是而知之 into 因反敵間而知敵情 “through conversion of the enemy’s spies we learn the enemy’s condition.” And Chang Yü says: 因是反間知彼鄉人之貪利者官人之有