'Fast' in the Bible

The Lord said to Satan, “Have you considered My servant Job? For there is no one like him on the earth, a blameless and upright man fearing God and turning away from evil. And he still holds fast his integrity, although you incited Me against him to ruin him without cause.”

Then his wife said to him, “Do you still hold fast your integrity? Curse God and die!”

“He trusts in his house, but it does not stand;He holds fast to it, but it does not endure.

“My foot has held fast to His path;I have kept His way and not turned aside.

“I hold fast my righteousness and will not let it go.My heart does not reproach any of my days.