अर्जुन
In plain words
Arjuna said: Seeing this gentle human form of Yours, Janardana, I have now regained composure and returned to my natural state.
Word for word
Having seen this gentle human form of Yours, O Janārdana, I have now become composed in mind [and] gone [back] to [my own] nature.
दृष्ट्वेदं मानुषं रूपं तव सौम्यं जनार्दनइदानीमस्मि संवृत्तः सचेताः प्रकृतिं गतः
Other commentaries
The commentators
▸Bhagavadgītābhāṣyam· bhāṣya
दृष्ट्वा इदं मानुषं रूपं मत्सखं प्रसन्नं तव सौम्यं जनार्दन, इदानीम् अधुना अस्मि संवृत्तः सञ्जातः । किम् ? सचेताः प्रसन्नचित्तः प्रकृतिं स्वभावं गतश्च अस्मि ॥ ५१ ॥
In plain words
Now that I have seen this human form of yours again, Janārdana — this form that treats me as a friend, that is gentle and calm — I have come back to myself. What does that mean? Śaṅkara answers: my senses have returned, my mind has settled, and I am simply myself again.
Close to the Sanskrit
Having seen this human form of yours, having me as a friend, gracious, gentle, O Janārdana, now, at this very moment, I am, I have become. What [has he become]? [He has become] possessed of consciousness, of a tranquil mind, and returned to [his own] nature, disposition.