Moch. Isnaeni’s scientific contributions

The sale and purchase of land-based on customary law in daily practice is still practiced by some people in Indonesia. The sale and purchase of land in customary law adhere to the principle of "tunai and terang" which means that the handover of rights by the seller is carried out simultaneously with payment by the buyer and immediately the rights have transferred. This research discusses the Ratio legis of the use of the principle of "tunai and terang" in the sale and purchase of land in Indonesia. The research method used is normative legal research with a statutory approach and a conceptual approach as a problem approach method. The results showed that the use of "tunai and terang" in the formation of sale and purchase agreements for land rights in Indonesia is because UUPA accommodates Customary Law as the basis for the National Land Law. The existence of cash and light principles is expected to provide legal protection for sellers and buyers.