Lenders do not just ask how much money you have. They ask where it came from and whether it can be documented. Moving money around at the wrong time is one of the most common reasons a file slows down.
Start with the cash to close guide, then read the guide for your source of funds.
Loan program pages: Down payment · Gifts and seller help by loan · Down payment help · VA down payment help
Cash to close
Cash to Close: How to Calculate the Money You Need
Cash to close is your down payment plus closing costs, prepaid items and escrow deposits, minus any credits and your earnest money. Here's how to estimate it before you shop.
Read: Cash to Close: How Much Money You Need to Buy a Home
Where the money can come from
Where the money can come fromRead: Where Your Down Payment Can Come From
Where the money can come fromRead: Mortgage Gift Funds