This phrase is not actually slang, but a standard Spanish phrase. It literally translates to 'you have to give the benefit of the doubt'. It is used when you are unsure about something or someone, but choose to remain positive or hold judgment until more information is known.
Examples
- Spanish: No sé si Juan robó las galletas, pero hay que darle el beneficio de la duda hasta que tengamos pruebas.
- English: I don't know if Juan stole the cookies, but we have to give him the benefit of the doubt until we have evidence.