Bhagavad Gita Chapter 6 Verse 3

Gita 6.3

आरुरुक्षोः, मुनेः, योगम्, कर्म, कारणम्, उच्यते,
योगारूढस्य, तस्य, एव, शमः, कारणम्, उच्यते।।3।।

Gita 6.3

AarurukshoH, muneH, yogam’, karm, kaarnam’, uchyate,
Yogaarudasya, tasya, ev, shamH, kaarnam’, uchyate ||3||

Translation: (Yogam’) In Yog i.e. bhakti (aarurukshoH) who aspires to become firm (muneH) for a reflective worshipper (karm) only the act of bhakti prescribed by scriptures (kaarnam’) cause i.e. the aim of bhakti (uchyate) is said to be (tasya) that (yogaarudasya) worshipper engrossed in bhakti (shamH) the absence of all desires only (ev) in reality (kaarnam’) the cause for doing bhakti (uchyate) is said to be. (3)

Gita 6.3: For a reflective worshipper who aspires to become firm in yog i.e. bhakti only the performance of acts of bhkti prescribed by the scriptures is said to be the cause i.e. the aim of bhakti. In reality, the absence of all desires only is said to be the cause for doing bhakti i.e. motive for that devotee engrossed in bhakti.