He should think carefully about actions like this which playinto the hands of his opponents.
他应该留神这类对对手有利的行为。
《柯林斯英汉双解大词典》
2
Quarrelling brothers could only playinto the hands of outsiders.
兄弟阋墙, 只能为他人所趁。
《新英汉大辞典》
3
She argued (with feeling) that the organization had lost sight of its original ideals, and had become a moonist militia that would only playinto the hands of the powers.