Asanga

Asanga was the fourth-century Indian philosopher and monk, who after twelve years of meditation finally received the encounter with Maitreya. When Asanga asked the Master why he had never appeared to him during those twelve years, Maitreya replied that he had been there all the time but Asanga had not seen him because he had not yet developed great compassion.

Sources

Pearls of Wisdom, vol. 31, no. 57.