Abstract: This study reconstructs the concept of khidmah students' devotional service to their teacher within the Islamic educational tradition through a philosophical-pedagogical approach. Amid the contemporary crisis of adab in education and the rapid digitalization of pesantren, khidmah is often reduced to physical service or suspected as feudal practice, despite harboring epistemological, relational, and transformative depths that remain systematically unexplored. Employing a qualitative-philosophical design, this study combines library research on classical texts (Hasyim Asyʼari's Adab al-ʼAlim wa al-Mutaʼallim, al-Zarnuji's Taʼlim al-Mutaʼallim, al-Ghazali's Ihyaʼ ʼUlum al-Din) with field research in Nusantara pesantren that preserve khidmah traditions, analyzed using reflexive thematic analysis. Three main findings are formulated: first, khidmah functions as a praxis of scholarly adab that prepares students' inner structure to receive knowledge as a trust rather than mere information; second, khidmah forms transformative teacher-student relationships through moral proximity, direct exemplarity, and the transmission of scholarly sanad; third, khidmah operates as a mechanism of character internalization through four pathways exemplarity, closeness, disciplined devotion, and communal legitimacy. This study offers a theoretical novelty in the form of the Trilogical Khidmah model, integrating al-Attas's taʼdib framework, Noddings's ethics of care, and Lickona's character education into a unified pedagogical synthesis. Its practical contribution provides direction for developing adab-based character curricula in Indonesian pesantren and madrasah, alongside a critical reading of authority abuses inherent in kiai-santri relations.