Scriptures and sacred texts affirm the efficacy of Bhakti as a sure means to salvation. The Bhagavata Purana extols the glory of the Supreme Being with the aim of imparting the value of true Bhakti.
The various incarnations of the Lord while reinforcing His supremacy, also reveal His boundless compassion for all created beings, said Sri R. Aravamudhachariar in a discourse. For it is in these divine descents to the earth that celestials and human beings alike witness His prowess on the one hand and His easy accessibility (Soulabhya) that the devout are privileged to experience. When the Lord incarnated as Vamana He took a small form hiding His greatness for the sake of retrieving the kingdom of Indra from the Asura king Bali.
He appeared as the handsome young Brahmachari with extraordinary glow and charm. He won the admiration, love and respect of all present during the performance of the Yaga by Bali. In response to Bali's generosity, Vamana asked him to give Him three feet of land that would be measured by His feet. Though severely warned by Sukracharya, Bali did not wish to go back on the given promise. Being a devotee of the Lord, he considered it a great blessing to be able to give to the Lord. Bali's daughter Ratnavali who was present was so impressed by the charming form of Vamana that she wished to be a mother to such a handsome young boy. But soon Vamana grew into Trivikrama whose first step spanned the earth and the next the entire heavens. He then asked Bali for further space . Bali immediately recognised the Supreme Being and was humbled. He bowed down and willingly offered his head for the Lord's third step.
Both Bali's children, Bana and Ratnavali became very angry at Vamana. Bana questioned the righteousness of the Lord's gesture and Ratnavali was filled with a desire to kill Him. Since the desire to be a mother to the Lord and also to kill Him co-existed in Ratnavali, she was born as the demoness Putana, who got the opportunity to fondle the child Krishna and at the same time feed him poisoned milk with the intention of killing Him.