All gifts which are inspired by the fervour of Upasana and the love of God are really Sattvic. In Tapas (austerity), Yajna (sacrifice) and Kirtan also, the cumulative powers of faith, love of God and keen longing for divine illumination produce full Sattvic benefits or fruits. Patanjali Maharshi emphasises in various places in his Raja Yoga Sutras on the importance of Upasana. For even a Raja Yogi, Upasana is necessary. He has his own Ishtam or guiding deity—Yogeshvara Krishna or Lord Siva. Self-surrender to God is an Anga (limb) of Raja Niyama and Kriya Yoga. Patanjali says, "One can enter into Samadhi through Upasana."