Newly awakened, the Buddha decides the truth he has found is too subtle to teach; Brahma Sahampati, lord of the high heaven, appears before him, kneels and begs him to teach for those with little dust in their eyes, and the Buddha agrees. In another sutta, Baka Brahma learns his heaven is not forever.
Under the Goatherd's Banyan by the Neranjara the Buddha thinks: what I have found is deep, hard to see, and this generation delights in attachment; if I teach and they do not understand, that would be tiresome. His mind inclines to dwelling at ease. Brahma Sahampati knows the thought in his own mind, thinks the world is lost, and, as quickly as a strong man straightens a bent arm, leaves the Brahma world and stands before him. He puts his robe over one shoulder, kneels on his right knee and folds his hands: let the Blessed One teach; there are beings with little dust in their eyes who will fall away if they do not hear. The Buddha surveys the world and sees it like a pond of lotuses, some under the water, some at its surface, some standing clear of it, and answers: open are the doors to the Deathless. Brahma bows, circles him, and vanishes.
Baka Brahma holds that his world is permanent, that it does not pass away and there is no escape beyond it. The Buddha goes up to the Brahma world and tells him he is wrapped in ignorance. Mara, speaking through one of Brahma's company, warns the Buddha not to oppose the creator. The Buddha names the heavens above Baka that Baka does not know. Baka says he will vanish from the Buddha and cannot. The Buddha vanishes from Baka and his whole assembly, and speaks verses to them while they cannot see him.