You must be able to guarantee the funds will be there to everyone's satisfaction. If you are waiting for a pay check that comes regularly to finalize your amount, that's one thing. If it's an inheritance or legal settlement, you may want to wait until it's in your account to be sure nothing goes wrong.
Discuss your specifics with your lender to get the best possible answer for your situation.
If you need more time putting together a down payment and are a first time buyer in NJ, there are many state grants for down payment funds, A lot of them are set up like second mortgages but you don't have a monthly bill and every year you live in the house you get 25% of the debt waived. If you stay in the house for 4 years it turns out to be free downpayment money . Check out the link below for more information . Good luck in your purchase.