SB 1.2 - Viṣṇu’s relation to the guṇas
The Lord is described as parama (beyond) because though He is linked with the guṇas, by His inconceivable energy He is situated separately from them, untouched by them. Viṣṇu is addressed as sattva-tanoḥ. This can only mean that Viṣṇu possesses a body of viśuddha-sattva as confirmed in SB 1.1.25, and not material sattva. In other Purāṇas also this is confirmed. Viṣṇu would not take up a body of material sattva because sattva has the qualities of revelation or knowledge and indifference to enjoyment. Sattva should not eclipse the spiritual manifestation of eternity, knowledge and bliss. Rajas agitates and causes addition (creation); and tamas is obscuring and causes subtraction (destruction). Thus rajas and tamas will disturb and cover bliss. Thus Brahmā and Śiva accept bodies of rajas and tamas because those guṇas eclipse bliss. They have bodies composed of guṇas, whereas Viṣṇu does not.
One cannot say that Viṣṇu’s existence beyond the guṇas is negated by His participation in the world, because He does not possess material sattva by relationship of contact or inherence. He is situated in sattva only by being next to it. His protection of His devotees also arises from śuddha-sattva of His svarūpa. Brahmā is a jīva since he is Hiraṇyagarbha, with a material body made of mahat-tattva. Only because of the powers conferred by the Lord on Brahmā, who is situated in rajas, he is considered an avatāra. The Brahma-saṁhitā confirms that Govinda becomes Brahmā, just as the sun displays a small portion of its powers of heat and light in all the sun stones which represent it.
Because Śiva is not a jīva, he is considered to be the Supreme Lord associated with the guṇas. Brahma-saṁhitā says Govinda becomes the form of Śiva, who is non different from Him, but who is also different because of his contact with the transformations of prakṛti. Some say that of Brahmā and Śiva, Śiva is īśvara or the Supreme Lord. Others say that he is connected with the guṇas. The verse (1.2.23) says ‘yuktaḥ parama-puruṣa’. Now yoga (related to yukta) means connection by proximity, by contact and by supervision. The puruṣa connected with the guṇas only as the supervisor is devoid of guṇas being situated in his svarūpa. Brahmā and Śiva, however, are connected to rajas and tamas by contact, and therefore called sa-guṇa, endowed with the guṇas.