These are the things for which no oath is imposed: slaves, legal documents, land, and consecrated property; neither is there twofold payment, nor fourfold nor fivefold payment. An unpaid shomer does not swear, a paid shomer does not pay. R' Shimon says: [Concerning] consecrated things for which one is responsible —- an oath is imposed; but [concerning] those for which one is not responsible —- no oath is imposed.