With the gods gone from heaven Aditi laments. Kashyapa, back from meditation, asks whether some household duty was neglected; she asks only that her sons' fortune be restored. He teaches the payovrata he learned from Brahma: in the bright fortnight of Phalguna, twelve days living on milk, with daily worship of Vishnu. Vishnu appears four-armed, says he will become her son to protect her other sons, and enters her womb through Kashyapa's meditation; Brahma offers prayers.
Srimad-Bhagavatam (Bhaktivedanta Vedabase) § 8.16; Srimad-Bhagavatam (Bhaktivedanta Vedabase) § 8.17
Vishvamitra tells Rama that the hermitage they have reached is where Vishnu did penance and was the dwarf: when Bali held the three worlds the gods begged Vishnu to take a dwarf's form; he asked three steps and covered earth, sky and heaven. Griffith's verse translation omits eight shlokas here and does not mention Aditi or her vow.
No Aditi, no vow in the lines Griffith translates; the gods ask Vishnu directly.
The Ramayan of Valmiki, tr. R. T. H. Griffith (1870-74) § 1.31
Sources: Srimad-Bhagavatam (Bhaktivedanta Vedabase); The Ramayan of Valmiki, tr. R. T. H. Griffith (1870-74)
Aditi bears eight sons, goes to the gods with seven and casts away the eighth, Martanda, then brings him back. Later texts explain why.
Naraka of Pragjyotisha steals Aditi's earrings; Krishna kills him and returns them, and Aditi blesses Krishna and Satyabhama.
Why the Soma sacrifice opens and closes with a pot of rice for Aditi: the earth, left out of the rite, confounds it until she is given a share.
The Rigveda's six, seven or eight Adityas become the twelve months in the Brahmanas and twelve named sun-gods in the Puranas.
In the Rigveda Vishnu's one deed is to take three steps that measure out the world and make room for people; the third step is a honeyed place out of sight. The Brahmanas turn the steps into earth, air and sky, the Ramayana gives them a dwarf and a king named Bali, and festivals in Kerala and the Deccan welcome that king home.
The Asuras have won the earth and are dividing it. They grant the gods only as much as Vishnu, a dwarf who is the sacrifice, can lie on; the gods enclose him with the metres and win the whole earth by worship. The Bhagavata Purana tells the bargain as Vamana and King Bali.
Diti's sons are killed by the gods.
The Maitri Upanishad names Brahma, Rudra and Vishnu together as portions of one being, matched to the three gunas.