Vandana is prayer and prostration. Humble prostration touching the earth with the eight limbs of the body (Sashtanga-Namaskara), with faith and reverence, before a form of God, or prostrations to all beings knowing them to be the forms of the One God, and getting absorbed in the Divine Love of the Lord is termed prostration to God. The Bhagavata says: The sky, air, fire, water, earth, stars, planets, the cardinal points (directions), trees, rivers, seas and all living beings constitute the body of Sri Hari. The devotee should bow before everything in absolute devotion, thinking that he is bowing before God Himself. Lord Krishna says to Uddhava: Giving no attention to those who laugh in ridicule, forgetting the body and insensible to shame, one should prostrate and bow down to all beings, even to the dog, the ass, the Chandala and the cow. All is Myself, and nothing is but Myself.
Arjuna does prostration to Krishna in a most beautiful manner: Salutation to You from the front, salutation to You from behind, salutation to You from every side! O All! Immeasurable in strength, You pervade all. You are all!
The object or purpose of Devotion is to realise God through exclusive love. The Mahabharata says: There is nothing which is more auspicious than Bhagavan Vasudeva, there is nothing more purifying than Vasudeva, and there is no Deva, worthy of being worshipped higher than Vasudeva. He who offers his salutations to Vasudeva suffers no afflictions.
Bhishma says: Even one bend of the head to Lord Sri Krishna is equal in merit to the completion of ten horse-sacrifices. The latter does not bring about Liberation, but the former makes one God Himself.
Akrura practised this kind of Bhakti, i.e., Vandana Bhakti. His story is given in the Srimad-Bhagavata. The Bhagavata says: Overwhelmed with devout love, Akrura quickly jumped down from the chariot and fell prostrate like a pole at the feet of Balarama and Sri Krishna. In the Mahabharata it is told that the old warrior Bhishma offered his salutation to the Lord in a voice choked with deep emotion and Sri Krishna immediately favoured him with the light of Divine Knowledge, Having thus offered his prayer to the Lord, Bhishma whose mind was wholly absorbed in God, said, 'Salutation to Krishna' and bowed his head to Him. Learning the depth of Bhishma's devotion, through His power of Yoga, Sri Hari, Madhava, bestowed upon Bhishma the light of Divine Knowledge which illuminates the three worlds.
The ego or Ahamkara is effaced out completely through devout prayer and prostration to God. The Divine grace descends upon the devotee and man becomes God.