Surely, the highest embodiment of compassion was one who had struggled through numerous rebirths towards the liberation that was nirvana, and on reaching the desired threshold, turned back to regard living beings with an all-embracing compassion, and then willingly reentered samsara in order to help the whole world achieve enlightenment. Siddhartha Gautama himself had therefore been a bodhisattva for the thirty-five years prior to his enlightenment, when he became the Buddha.
Indeed, early images of Siddhartha shortly before his enlightenment are accordingly often termed 'bodhisattva.' Nevertheless, the theory that the Buddha had disallowed his images is more prevalent.
The Buddha image, without which the sculptural art of South Asia would have been deprived not only of its major bulk but also much of its stylistic versatility and spiritual fervor, has constantly been under debate as to its origin and evolution.
Some believe that the first Buddha image had come into being during the lifetime of the Buddha himself.
These scholars contend that the tradition so begun continued ever since, but the medium, wood or clay, generally used for making these images, being of perishable nature, could not have such images survive against time.
The legend of king Udayana, which appears in the Chinese version of the Anguttara Nikaya, supports this view.
This text of the Anguttara Nikaya, translated into Chinese sometime between the first and the third century A. from a Korean translation of the scripture, obviously a work of an earlier date, contends that the Buddha, after he was Enlightened, wished to sermonize his mother Maya who, having passed away, was in the Trayatrimsa heaven (Realm of the thirty-three gods). After three months, Buddha descended back from Trayatrimsa.
Buddha hence left this world for three months and went there. According to the legend, king Udayana, on his return, showed the image to the Buddha who thereupon preached the great virtue of making the Buddha image.This story of king Udayana commissioning the Buddha image is said to have been recorded also by Fa-hsien and later by Hsuan Tsang in their travel accounts. Adhering to tradition, the Japanese replica is worshipped by offering pouches of sandalwood powder.One of the most sacred Buddha images in Japan is revered as being the replica of the above-mentioned king Udayana's Buddha image. This legend of the origin of the Buddha image is yet prevalent and largely believed in Tibet, China and Japan.This image was acclaimedly brought from China to Japan in 986 A. For most scholars however, logically basing their opinions on the antiquity of available art objects, the earliest Buddha images come from around the first century B.C., some five hundred year after Buddha's Mahaparinirvana.These occur on Kushana dynasty coins datable to 150 to 50 B. having human figures on them, which some identify as the Buddha.