“The word śāntam means “always in the same form.” Śāntam can also mean “undisturbed, free from passion, or purified.” According to Vedic philosophy, all change in this world is caused by the influence of passion and ignorance. The passionate mode is creative, and the ignorant mode is destructive, whereas the mode of goodness, sattva, is serene and sustaining. In many ways this verse emphasizes that Lord Kṛṣṇa is free from the modes of nature. The words viśuddha-sattvam, śāntam, dhvasta-rajas-tamaskam and guṇa-sampravāho na vidyate te all indicate this. Unlike Kṛṣṇa, we change from one body to another because of our involvement with the modes of nature; the various transformations of material forms are impelled by the modes of nature, which are themselves set in motion by the influence of time. Therefore one who is free from the material modes of nature is changeless and eternally satisfied in blissful spiritual existence. Thus the word śāntam indicates that the Lord is undisturbed by change, since He is free from the material modes of nature.
Source:A.C. Bhaktivedanta Swami Prabhupada (2014 edition), “Srimad Bhagavatam”, Tenth Canto, Chapter 27 – Text 04