Definition from Wiktionary, the free dictionary
- 打 dǎ ("to buy") + 醬油 jiàngyóu ("soy sauce"). Popular Internet meme popularised in 2008 by a man-on-the-street's response to a television reporter's question about a recent celebrity photo scandal, to which the man replied, "What's it got to do with me? I'm here to buy soy sauce."
- (slang) to be none of someone's business; to not involve one
- Usually used to express one's reluctance to discuss sensitive issues, sometimes in a jocular or sarcastic fashion.