'Fast' in the Bible

But now he is dead; why should I [continue to] fast? Can I bring him back again? I will go to him [when I die], but he will not return to me.”

Now Absalom met the servants of David. Absalom was riding on his mule, and the mule went under the thick branches of a massive tree, and his head was caught in [the thick branches of] the tree; and he was left hanging [in midair] between heaven and earth, while the mule that had been under him kept going.