Upon the allowance of claims by the city council of a city of the second class or village board of trustees, the order for their payment shall specify the particular fund or appropriation out of which they are payable as specified in the adopted budget statement; and no order or warrant shall be drawn in excess of eighty-five percent of the current levy for the purpose for which it is drawn, unless there shall be sufficient money in the treasury at the credit of the proper fund for its payment. In the event there exists at the time such warrant is drawn, obligated funds from the federal government or the State of Nebraska, or both from the federal government and the State of Nebraska, for the general purpose or purposes of such warrant, then such warrant may be drawn in excess of eighty-five percent of the current levy for the purpose for which it is drawn to the additional extent of one hundred percent of such obligated federal or state funds. No claim shall be audited or allowed unless an order or warrant for the payment thereof may legally be drawn.