Answer: Brihadaranyaka Upanishad
Notes: According to Brihadaranyaka Upanishad, the King of Videha used to give gold coins and cows as gift. The Brihadaranyaka Upanishad is one of the Principal Upanishads and one of the first Upanishadic scriptures of Hinduism. The Kingdom of the Videhas was an ancient Indian kingdom in Late Vedic India which rose to prominence under King Janaka. The ancient kingdom's territory is located in Mithila region on the northern part of the Indian subcontinent, what is today northeastern Bihar of India and the eastern Terai of Nepal.
