朝マラの立たぬ男に金貸すな（あさマラのたたぬおとこにかねかすな）

Japanese vocabulary

Meaning: do not lend money to a man who doesn't have an erection in the morning (because he is not in good health and might die before he can repay)

See it used in real works

• Example sentences from Japanese novels & web fiction (Massif)
• Hear “朝マラの立たぬ男に金貸すな” pronounced in real videos (YouGlish)