按兵不动 ànbīng-bùdòng
(1) [not throw the troops into battle;take no action;be kept imobilized;bide one's time]∶指挥官止住军队,暂不行动,等待战机
(2) [bide one's time]∶比喻接受任务后暂不执行,以观望形势的发展