श्री भगवानुवाच मय्यासक्तमनाः पार्थ योगं युञ्जन्मदाश्रयः। असंशयं समग्रं मां यथा ज्ञास्यसि तच्छृणु ॥

mayyāsakta-manāḥ pārtha yogaṁ yuñjan mad-āśhrayaḥ asanśhayaṁ samagraṁ māṁ yathā jñāsyasi tach chhṛiṇu

With the mind clinging to me, O Pârtha, performing yoga, refuged in Me, how thou shalt without doubt know Me to the uttermost, that hear thou.

In plain words: Krishna tells Arjuna (called Pārtha, "son of Prithā") to listen. He will explain how Arjuna can know him fully and without doubt by keeping his mind on Krishna, practicing yoga, and taking shelter in him.