When lenders review your loan for approval, one of the things they study is the source of funds for your down payment and closing costs. Most lenders will ask that you provide statements for the last two or three months on any of your liquid assets. This includes things like:
checking accounts, savings accounts, money market funds, certificates of deposit, stock statements, mutual funds, and your retirement accounts.
The lender will likely require a paper trail of all the withdrawals and deposits. You will be required to produce cancelled checks, deposit receipts, and other data, which could get quite tedious. They are only doing their job correctly. To ensure quality control and eliminate potential fraud, it is a requirement on most loans to completely document the source of all funds.
Moving your money around, even if you are consolidating your funds could make it more difficult for the lender to properly document.
So, leave your money where it is until you talk to a loan officer.