In plain words
Those whose voice is not right, who have no tune or rhythm, hum away in the bathroom at least. So Kṛṣṇa's voice was clear indeed, and His singing was full of tune and rhythm indeed; on the battlefield, on the field of welfare, He went on singing the Gītā. That is exactly why it has the fitting name Bhagavad Gītā. Gītā means song. Truly, would there be anyone who sings a song on a battlefield, but for Kṛṣṇa alone? For God, wherever He is, there is nothing but Ānanda. He Himself is full of Ānanda. So this śloka has been teaching that to try to receive His Ānanda, to give ourselves up wholly to this One full of Ānanda, is the sacred path.
Students, embodiments of Prema! There is no need for you to be careless in giving the body enough nourishment and enough strength and ability; but, with the truth that this is a body that has come, in this frame, to win Dharma in the land of Bhārata, I hope that you will bow to the command of the elders in the practice of Dharma, keep our Bhāratīya culture in view and, in time to come, for the establishing of Dharma and to uphold this sacred culture, make these bodies, with strength and ability, and the mind too, sacred, fittingly for it, and take part in this work.