In plain words
To those who are ever intent and worship Me with love, I give buddhi-yoga by which they come to Me.
Word for word
To them, ever intent, worshipping with love, I give that buddhi-yoga by which they come to Me.
The commentators
Bhagavadgītābhāṣyam
ये यथोक्तैः प्रकारैः भजन्ते मां भक्ताः सन्तः —
तेषां सततयुक्तानां नित्याभियुक्तानां निवृत्तसर्वबाह्यैषणानां भजतां सेवमानानाम् । किम् अर्थित्वादिना कारणेन ? नेत्याह — प्रीतिपूर्वकं प्रीतिः स्नेहः तत्पूर्वकं मां भजतामित्यर्थः । ददामि प्रयच्छामि बुद्धियोगं बुद्धिः सम्यग्दर्शनं मत्तत्त्वविषयं तेन योगः बुद्धियोगः तं बुद्धियोगम् , येन बुद्धियोगेन सम्यग्दर्शनलक्षणेन मां परमेश्वरम् आत्मभूतम् आत्मत्वेन उपयान्ति प्रतिपद्यन्ते । के ? ते ये मच्चित्तत्वादिप्रकारैः मां भजन्ते ॥ १० ॥
In plain words
Those who worship me in the ways just described, and who are devotees in doing so —
To those who are constantly engaged, perpetually devoted, who have turned entirely away from every outward craving, who worship me, who serve me — not from any need of theirs, but purely out of love, out of affection — I give exactly this: the yoga of understanding, the clear right vision whose only object is who I truly am, the very yoga by which they come to me, the Supreme Lord, as their own Self. And who are these people? Those who, with their whole mind set on me and in every way like it, worship me.
Close to the Sanskrit
Those who, by the aforesaid modes, worship me, being devotees —
To them — constantly engaged, perpetually devoted, who have turned back from all external cravings, who worship, who serve — [what do I give]? For what reason, neediness or the like? He says: No — preceded by love; love is affection; preceded by that, of those who worship me [with love]; this is the meaning. I give, I bestow, the yoga of understanding; buddhi is right vision, having my true nature as its object; by that, yoga is union — the yoga of understanding; that yoga of understanding, by which yoga of understanding, characterized by right vision, they approach, they attain, me, the Supreme Lord, become the Self, in the capacity of the Self. Who? They who, by ways such as having their mind fixed on me, worship me.