As a fascinating weapon, Rencong Aceh cannot be separated from the life of Acehnese people. In order to describe the morphology of which, a qualitative method was implemented to collect the data through observation, interview and document analysis. The collected data were analyzed with descriptive analysis. The four types of Rencong Aceh – rencong meucugek, rencong meukuree, and rencong podoi or puntong – have the structure of Bismillahirrahmanirrahim entirely. Those also possess the letter of Ba. Every morphology form of Rencong Aceh is constant, either in the form of Bismillāh, Bismillāhirrahmanirrahim, or Ba. Philosophically, the compilation of morphology upon the weapons cannot be disconnected from the Islamic context developed within the social and culture understanding and its practice of the Acehnese people. Every beginning of an action should be initiated with the words of Bismillāhirrahmanirrahim. The expression is done to get the mercy and blessing of God, particularly when the enemies attack.