<p>This study explores the indigenous oath-taking practice of the Mao-Naga tribe in Northeast India, known as <i>echa-a echo-o</i>, situating it within the global Rights of Nature discourse. The analysis highlights how the Mao-Naga’s ecological worldview anticipates contemporary principles of environmental personhood and legal pluralism. Drawing on interviews with village elders, the research interprets <i>echa-a echo-o</i> as a form of Indigenous ecological jurisprudence, in which natural entities, stones, plants, earth, and the sun, along with the immanent Supreme God <i>Oramei</i>, act as witnesses and moral guarantors of truth. By linking this practice to Earth Jurisprudence and Indigenous Ecological Knowledge, the paper demonstrates that Mao-Naga customary law embodies a vernacular model of ecocentric accountability, challenging anthropocentric assumptions that marginalise tribal legal thought. The findings argue that indigenous judiciary systems, though distinct from state institutions, possess coherent frameworks of justice grounded in ecological balance and moral reciprocity. The study thus contributes to bridging the gap between indigenous and mainstream legal discourses, advocating for the recognition of customary ecological jurisprudence as a legitimate expression of the Rights of Nature within plural legal systems.</p>