飲馬投錢 (jam3 maa5 tau4 cin2) — to pay for what one has got in Cantonese
jam˗₃飲maaˏ₅馬tauˎ₄投cinˊ²錢简 饮马投钱
Mandarin Pinyin: yin3 ma3 tou2 qian2
Meaning of 飲馬投錢
nounto pay for what one has got
nounliterally: 'to pay even for a horse's drink of water', to describe the extreme honesty of someone who does not seek private gain at public expense, who has integrity and probity