The rencong is a traditional Indonesian weapon in the form of a dagger. It is the weapon of choice among the inhabitants of the island of Aceh. During the Aceh war (1873–1904 CE) the people of Aceh fought a heavy battle against the Dutch who attempted to colonize the island and its people in order to incorporate the region into the former Dutch East Indies. However, the Acehnese military was remarkably well equipped with their deadly rencong daggers, which eventually forced the Dutch occupiers to retreat and admit defeat.
Hence, to this very day Indonesians commonly believe that the rencong possesses certain kinds of esoteric powers which can offer protection against all sorts of evil. This is also why a lot of practitioners of traditional Indonesian martial arts (e.g. pencak silat and pukulan) often claim to have mastered supernatural powers such as invulnerability (kanuragan) and invincibilty (kadigdayaan) by using a rencong dagger for this particular purpose. Indeed, if the dagger is properly made and blessed according ancient tradition, then the rencong can even increase the human body's immunity (kekebalan) against physical injuries caused by stab and gun shot wounds.
The blade of the talismanic rencong dagger is forged from sacred brass, which was obtained from a local mosque in Banda Aceh. During the forging process there are various kinds of powerful Islamic spells in the Arabic script embossed on the exterior surface of the blade. Thus, the blade is empowered with mystical properties of authentic Indonesian occult tradition, turning the dagger into a most powerful talisman for protection. Due to its relatively small size, the talismanic rencong dagger can be easily carried along in one's pocket, or tucked in one's sarong like they do in Indonesia. When at home the rencong should be placed on one's home altar along with other mystical objects. It can also be hung on the wall inside the house, or placed on a shelve or cupboard in the room where one normally performs ritual worship and spiritual practice.
Before removing the blade from its sheath, one should always recite the Basmala prayer (bismillāhi raḥmāni raḥīm) three times first. For the rest, it is strongly recommended to anoint the blade of the rencong with pusaka oil (i.e., magical oils extracted from fragrant flowers and other sacred herbal ingredients) every once in a while. This is considered an essential part of ritual worship which serves to maintain a harmonious relationship between this world and the Unseen.