'Fast' in the Bible

Blessed is the man who does this, and the son of man who holds it fast; who keeps the Sabbath from profaning it, and keeps his hand from doing any evil."

For thus says Yahweh, "To the eunuchs who keep my Sabbaths, and choose the things that please me, and hold fast my covenant:

Also the foreigners who join themselves to Yahweh, to minister to him, and to love the name of Yahweh, to be his servants, everyone who keeps the Sabbath from profaning it, and holds fast my covenant;

Why have we fasted,' [say they], 'and you don't see? [why] have we afflicted our soul, and you take no knowledge?' "Behold, in the day of your fast you find pleasure, and exact all your labors.

Behold, you fast for strife and contention, and to strike with the fist of wickedness: you don't fast this day so as to make your voice to be heard on high.

Is such the fast that I have chosen? the day for a man to afflict his soul? Is it to bow down his head as a rush, and to spread sackcloth and ashes under him? Will you call this a fast, and an acceptable day to Yahweh?

"Isn't this the fast that I have chosen: to release the bonds of wickedness, to undo the bands of the yoke, and to let the oppressed go free, and that you break every yoke?