'Fast' in the Bible

The three sons of Zeruiah were there: Joab, Abishai, and Asahel. Asahel was a fast runner, like one of the wild gazelles.

But now that he is dead, why should I fast? Can I bring him back again? I’ll go to him, but he will never return to me.”

Absalom was riding on his mule when he happened to meet David’s soldiers. When the mule went under the tangled branches of a large oak tree, Absalom’s head was caught fast in the tree. The mule under him kept going, so he was suspended in midair.