Haṭha Pradīpikā Chapter One verse 2

प्रणम्य श्रीगुरुं नाथं स्वात्मारामेण योगिना ।
केवलं राजयोगाय हठविद्योपदिश्यते ॥

praṇamya śrī-guruṃ nāthaṃ svātmārāmeṇa yoginā |
kevalaṃ rāja-yogāya haṭha-vidyā-upadiśyate ||

Yogin Svātmārāma,
after saluting first his Guru Śrī Nātha,
taught knowledge of Haṭha Yoga
only for the sake of Raja Yoga.

praṇam - to bend or bow down before; make obeisance tośrī - blessedguru - heavy, weighty; a teacher, preceptor; a spiritual parent or preceptor; any venerable or respectable personnātha - a protector, patron, possessor, owner, lordsvātmārāma - name of an authorkevala - alone, only, mere, sole, one, excluding othersrāja - a king, sovereign, chief or best of its kindyoga - the act of yoking, joining, attaching, harnessing; a yoke, team, vehicle, conveyance; employment, use, application, performance; a means, expedient, device, way, manner, methodhaṭha - force, forceful; by force, forciblyvidyā - any knowledge whether true or false; knowledge of the soul or spiritual knowledge; true knowledge; science, learning, scholarship, philosophyupadiśya - having indicated or taught; indicating, teaching