This study examines the ethical significance of the Javanese proverb Ajining Diri saka Lathi and its relationship to Islamic speech ethics. It addresses three questions concerning the meaning of the proverb within Javanese culture, the conceptualization of speech ethics in Islamic teachings, and the ethical convergences and differences between the two frameworks. This qualitative library research employs a comparative ethical-hermeneutic approach. The Javanese data comprise Ajining Diri saka Lathi and scholarly sources addressing Javanese ethics, communication practices, dignity, respect, and social harmony. The Islamic data comprise relevant Qur'anic verses, Prophetic hadiths, and classical and contemporary works of tafsīr and Islamic scholarship. The data were analyzed through identification, thematic categorization, contextual interpretation, comparison, and synthesis. The findings reveal substantial convergence between the two traditions in associating speech with moral character and emphasizing self-restraint, respect for others, and social harmony. However, the comparison also identifies a significant difference in their normative foundations and scope of accountability. In the Javanese sources examined, the ethical consequences of speech are primarily articulated through personal dignity, social recognition, and harmonious interpersonal relations. Islamic speech ethics encompass these concerns while extending them to a transcendental dimension in which speech is subject to divine evaluation and accountability before Allah and in the hereafter. The study contributes to the discussion of local wisdom and Islamic ethics by demonstrating how Javanese speech ethics can be placed in dialogue with Islamic teachings while preserving the distinct cultural and theological foundations of each tradition.