Bg 8.2

adhiyajnah katham ko ’tra
dehe ’smin madhusudana
prayana-kale ca katham
jneyo ’si niyatatmabhih

Word for word: 
adhiyajnah — the Lord of sacrifice; katham — how; kah — who; atra — here; dehe — in the body; asmin — this; madhusudana — O Madhusudana; prayana-kale — at the time of death; ca — and; katham — how; jneyah asi — You can be known; niyata-atmabhih — by the self-controlled.

Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Who is the Lord of sacrifice, and how does He live in the body, O Madhusudana? And how can those engaged in devotional service know You at the time of death?

Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
“Lord of sacrifice” may refer to either Indra or Visnu. Visnu is the chief of the primal demigods, including Brahma and Siva, and Indra is the chief of the administrative demigods. Both Indra and Visnu are worshiped by yajna performances. But here Arjuna asks who is actually the Lord of yajna (sacrifice) and how the Lord is residing within the body of the living entity.

Arjuna addresses the Lord as Madhusudana because Krishna once killed a demon named Madhu. Actually these questions, which are of the nature of doubts, should not have arisen in the mind of Arjuna, because Arjuna is a Krishna conscious devotee. Therefore these doubts are like demons. Since Krishna is so expert in killing demons, Arjuna here addresses Him as Madhusudana so that Krishna might kill the demonic doubts that arise in Arjuna’s mind.

Now the word prayana-kale in this verse is very significant because whatever we do in life will be tested at the time of death. Arjuna is very anxious to know of those who are constantly engaged in Krishna consciousness. What should be their position at that final moment? At the time of death all the bodily functions are disrupted, and the mind is not in a proper condition. Thus disturbed by the bodily situation, one may not be able to remember the Supreme Lord. Maharaja Kulasekhara, a great devotee, prays, “My dear Lord, just now I am quite healthy, and it is better that I die immediately so that the swan of my mind can seek entrance at the stem of Your lotus feet.” The metaphor is used because the swan, a bird of the water, takes pleasure in digging into the lotus flowers; its sporting proclivity is to enter the lotus flower. Maharaja Kulasekhara says to the Lord, “Now my mind is undisturbed, and I am quite healthy. If I die immediately, thinking of Your lotus feet, then I am sure that my performance of Your devotional service will become perfect. But if I have to wait for my natural death, then I do not know what will happen, because at that time the bodily functions will be disrupted, my throat will be choked up, and I do not know whether I shall be able to chant Your name. Better let me die immediately.” Arjuna questions how a person can fix his mind on Krishna’s lotus feet at such a time.