Whether it was a gift or you borrowed it and plan to pay it back, don't ever think it's harmless to declare it as part of your genuine savings. You'll have to disclose the source of your down payment to avoid the risk of being questions, or worse, being outright denied on your loan. Don't exaggerate your income to make yourself look more financially stable or switch employers at any point in the buying process.
If something doesn't add up, you better be prepared to explain exactly what's happening. Failing to disclose your debts, no matter how small, could prove to be a problem later on and can hurt your chances of getting a mortgage.
