Definition
This idiom advises against being critical or unappreciative of a gift or favor that someone has offered.
不要對获得的好處挑三到四。
She gave me an old sweater, and even though it was a bit outdated, I accepted it graciously, remembering not to look a gift horse in the mouth.
她給了我一件舊毛衣，雖然有點過時，但我還是欣然接受了，記得不要挑剔別人送的禮物。
When you receive something for free, remember not to look a gift horse in the mouth.
當你收到免費的東西時，記得不要對禮物吹毛求疵。
They offered us free lodging, and even though it wasn't a five-star hotel, we shouldn't complain; after all, you don't look a gift horse in the mouth.
他們提供我們免費住宿，雖然不是五星級飯店，但我們不應該抱怨；畢竟，不要對免費的東西挑剔。