SB 2.2.15
sthiram sukham casanam asthito yatir
yada jihasur imam anga lokam
kale ca dese ca mano na sajjayet
pranan niyacchen manasa jitasuh
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
O King, whenever the yogi desires to leave this planet of human beings, he should not be perplexed about the proper time or place, but should comfortably sit without being disturbed and, regulating the life air, should control the senses by the mind.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
In the Bhagavad-gita (8.14) it is clearly stated that a person who is totally engaged in the transcendental loving service of the Lord, and who constantly remembers Him at every step, easily obtains the mercy of the Lord by entering into His personal contact. Such devotees do not need to seek an opportune moment to leave the present body. But those who are mixed devotees, alloyed with fruitive action or empirical philosophical speculation, require an opportune moment for quitting this body. For them the opportune moments are stated in the Bhagavad-gita (8.23-26). But these opportune moments are not as important as one’s being a successful yogi who is able to quit his body as he likes. Such a yogi must be competent to control his senses by the mind. The mind is easily conquered simply by engaging it at the lotus feet of the Lord. Gradually, by such service, all the senses become automatically engaged in the service of the Lord. That is the way of merging into the Supreme Absolute.