【顺水人情】〖shùn shu rén qíng〗[do sth. regarded as a favour without patting trouble to oneself; a friendly gesture without extra cost to oneself; a favour done at little cost]

顺理成章著诗典，

水滴石穿汉英翻。

人存政举凝人类，

情巧万端大同寰。

利用机会顺便给人的好处。也指不费力的人情。utilize opportunity Give person benefits. Also refers effortless human feelings. 同：顺手人情。谜：我解缆绳你推船。