The spiritual concept of Brahman is far older in the Vedic literature, and some scholars suggest deity Brahma may have emerged as a personal conception and icon with form and attributes (saguna version) of the impersonal, nirguna (without attributes), formless universal principle called Brahman. In the Hindu texts, one of the earliest mention of deity Brahma along with Vishnu and Shiva is in the fifth Prapathaka (lesson) of the Maitrayaniya Upanishad, probably composed in late 1st millennium BCE, after the rise of Buddhism.