financial aid while I-485 pend

I have a question needing your help.

I am thinking to buy a small house (I have been paying rent for too many years) and our city can aid me up to $7500 for the downpayment. After talked to related officer, I was told that I am qualified to get this aid. But my friend told me should be cautious because this may affect my pending I-485 negatively. Does what he says true?

Thanks for your helps.