The sale shall be upon six months' credit; and, if the land be not purchased for the state, the officer shall take the note of the purchaser with sureties for the payment of the purchase money to the state. Every such note shall mention on what occasion the same was taken and shall be returned to the office of the court from which the execution issued, and the clerk shall indorse thereon the date of its return. The officer and his sureties shall be liable to the state if insufficient security be taken on such bond.