Vala (valá-), meaning "enclosure" in Vedic Sanskrit, is a demon mentioned in the Vedas, including the Rigveda and the Atharvaveda. Vala is attributed to be the son of Tvashtr and therefore the brother of Vrtra.
Historically, it has the same origin as the Vrtra story, being derived from the same root, and from the same root also as Varuna, *val-/var- (PIE *wel-) "to cover, to enclose" (perhaps cognate to veil).
Parallel to Vrtra "the blocker", a stone serpent slain by Indra to liberate the rivers, Vala is a stone cave, split by Indra (intoxicated and strengthened by Soma, identified with Brhaspati in 4.50 and 10.68 or Trita in 1.52, aided by the Angirasas in 2.11), to liberate the cows and Ushas, hidden there by the Panis.
Already in 2.24, the story is given a mystical interpretation, with warlike Indra replaced by Brahmanaspati, the lord of prayer, who split Vala with prayer (brahman) rather than with the thunderbolt.
Vala is mentioned 23 times in the Rigveda, Vala appears in hymns RV 1.11, 52, 62, RV 2.11, 12, 14, 15, 24, RV 3.30, 34, RV 4, 50, RV 6.18, 39, RV 8.14, 24, RV 10.67, 68, 138.
Central verses of the story (trans. Griffith):