So the Śrīmad-Bhāgavata says that if you want to be free . . . free means just like you are trying to go to the moon planet by so many mechanical arrangements, but if you are free spiritually, then you can go any planet you like, immediately. The yogīs, those who are perfect yogīs—not these nonsense yogīs—those who are perfect yogīs, they can go at their will any planet they like. That is yogic perfection. When a yogī becomes perfect, he dies . . . he does not die. "Die," this word is not actually applicable.
When he leaves this body . . . actually, nobody will die. We simply quit this body and accept another body. We are forced by the laws of nature according to karma. By practice of yoga system we can avoid the forcible nature's law, but we can leave this body according to our sweet will, not being forced by the nature's law. Just like Bhīṣmadeva. Bhīṣmadeva, he knew this yoga practice. Therefore he was not to be killed. Unless he desired to die, nobody could kill him.