Unless the purchase is for cash, contracts are subject to and conditioned upon the buyer obtaining a loan in order to finance the purchase. The more detailed the description of the loan the more legal, i.e., particular bank, loan amount, interest rate and term of repayment. If the bank refuses the loan through what amounts to no fault of the buyer, the contract will fail and the binder will be refunded to the purchaser.
The more sophisticated contracts will spell out the amount of time given to the buyer to make the application and the time within which the bank can respond by approving or disapproving the loan. You need to pay particular attention to these contractual time limits and corresponding notifications and work with your agent to make sure you are conforming. The penalty for failure to comply is the removal of the financing contingency so that the contract is no longer subject to that contingency.