One example of the symbolic interpretation of Vishnu's form is mentioned in the Vishnu Purana.
PARÁŚARA. (says) --Having offered salutation to the mighty and indescribable Vishńu, I repeat to you what was formerly related to me by Vaśisht́ha. The glorious Hari wears the pure soul of the world, undefiled, and void of qualities, as the Kaustubha gem. The chief principle of things (Pradhána) is seated on the eternal, as the Srivatsa mark. Intellect abides in Mádhava, in the form of his mace. The lord (Íśwara) supports egotism (Ahankára) in its twofold division, into elements and organs of sense, in the emblems of his conch-shell and his bow. In his hand Vishńu holds, in the form of his discus, the mind, whose thoughts (like the weapon) fly swifter than the winds. The necklace of the deity Vaijayantí, composed of five precious gems 8, is the aggregate of the five elemental rudiments. Janárddana bears, in his numerous shafts, the faculties both of action and of perception. The bright sword of Achyuta is holy wisdom, concealed at some seasons in the scabbard of ignorance. In this manner soul, nature, intellect, egotism, the elements, the senses, mind, ignorance, and wisdom, are all assembled in the person of Hrishikeśa. Hari, in a delusive form, embodies the shapeless elements of the world, as his weapons and his ornaments, for the salvation of mankind 9. Puńd́arikáksha, the lord of all, assumes nature, with all its products, soul and all the world. All that is wisdom, all that is ignorance, all that is, all that is not, all that is everlasting, is centred in the destroyer of Madhu, the lord of all creatures. The supreme, eternal Hari is time, with its divisions of seconds, minutes, days, months, seasons, and years: he is the seven worlds, the earth, the sky, heaven, the world of patriarchs, of sages, of saints, of truth: whose form is all worlds; first-born before all the first-born; the supporter of all beings, himself self-sustained: who exists in manifold forms, as gods, men, and animals; and is thence the sovereign lord of all, eternal: whose shape is all visible things; who is without shape or form: who is celebrated in the Vedanta as the Rich, Yajush, Sáma, and Atharva Vedas, inspired history, and sacred science. The Vedas, and their divisions; the institutes of Manu and other lawgivers; traditional scriptures, and religious manuals 10; poems, and all that is said or sung; are the body of the mighty Vishńu, assuming the form of sound. All kinds of substances, with or without shape, here or elsewhere, are the body of Vishńu. I am Hari. All that I behold is Janárddana; cause and effect are from none other than him. The man who knows these truths shall never again experience the afflictions of worldly existence.