《明史·列传·卷二百零八》
副总兵祖承训带兵渡过鸭绿江援救史儒，结果败退，只身而还。
副总兵祖承训统兵渡鸭绿江援之，仅以身免。
Vice Chief Commander Zu Chengxun led his troops to cross the Yalu to rescue Shi Ru, and was defeated, returning alone.
<s>[INST] Kindly elucidate the central themes in this passage in English: 副总兵祖承训统兵渡鸭绿江援之，仅以身免。 [/INST] Vice Chief Commander Zu Chengxun led his troops to cross the Yalu to rescue Shi Ru, and was defeated, returning alone.</s>
Kindly elucidate the central themes in this passage in English: 副总兵祖承训统兵渡鸭绿江援之，仅以身免。
user
Vice Chief Commander Zu Chengxun led his troops to cross the Yalu to rescue Shi Ru, and was defeated, returning alone.
assistant