Bhagavad Gita Chapter 10, Verse 17

कथं विद्यामहं योगिंस्त्वां सदा परिचिन्तयन् | केषु केषु च भावेषु चिन्त्योऽसि भगवन्मया ||

kathaṁ vidyām ahaṁ yogins tvāṁ sadā paricintayan keṣu keṣu ca bhāveṣu cintyo 'si bhagavan mayā

How can I know You, O Yogi, by constantly meditating on You? In what various forms are You to be contemplated, O Blessed Lord?

Arjuna asks how to meditate on Krishna constantly. 'Kathaṁ vidyām ahaṁ yogins tvāṁ'—how can I know You, O Yogi. Arjuna addresses Krishna as 'yogin'—one who is united with Yoga. 'Sadā paricintayan'—constantly meditating on. Arjuna wants to know how to meditate on Krishna constantly, not just occasionally. 'Keṣu keṣu ca bhāveṣu cintyo 'si'—in which various forms are You to be contemplated. Arjuna recognizes that Krishna can be contemplated in various forms and wants to know which forms. 'Bhagavan mayā'—O Blessed Lord, by me. Arjuna is asking for practical guidance: how to meditate on Krishna constantly, and in which forms to contemplate Him. This shows his eagerness to practice what Krishna has been teaching.