Newly born in the lotus and surrounded by dark water, Brahma turns to look in every direction, and a face forms wherever he looks. The four heads are a record of that first searching gaze. Later convention reads them as the four Vedas and the four quarters of space.
Srimad-Bhagavatam 3.8 — Bhaktivedanta Vedabase; Brahma — Wikipedia
The Matsya Purana ties the heads to desire. Brahma's body divides into a male and a female half, and the female half becomes Saraswati. Struck by her beauty, he wishes to keep her in view as she moves around him, and a new head appears on each side so that he need never turn away.
The heads grow from desire for the daughter, not from looking about the empty water; this is the version the Skanda Purana uses to explain the fifth head.
Sources: Srimad-Bhagavatam 3.8 — Bhaktivedanta Vedabase; Brahma — Wikipedia; Saraswati — Wikipedia
The Maitri Upanishad names Brahma, Rudra and Vishnu together as portions of one being, matched to the three gunas.
The sage Atri and his wife Anasuya earn great merit through their conduct and austerity.
A seven-metre three-faced bust fills the south wall of Elephanta's Cave 1.
Three Pallava shrines on one platform: Shiva in the centre, Vishnu on the right, and a disputed left shrine read as Brahma by Vogel but as Subrahmanya or Brahmasasta by later scholars; a Durga panel stands beside.
Before the gods there are only the primordial waters.
A golden egg forms in the waters and glows like the sun.
During the dissolution Vishnu lies on the serpent Ananta in the cosmic waters.
Shiva alone exists before the world.