'Fast' in the Bible

I know thy works, and where thou dwellest, even where Satan's seat is: and thou holdest fast my name, and hast not denied my faith, even in those days wherein Antipas was my faithful martyr, who was slain among you, where Satan dwelleth.

But I have a few [things] against you: that you have there those who hold fast to the teaching of Balaam, who taught Balak to put a stumbling block before the sons of Israel, to eat food sacrificed to idols and to commit sexual immorality.

So likewise you also have those who hold fast to the teaching of the Nicolaitans.

But that which ye have already hold fast till I come.

Remember therefore how thou hast received and heard, and hold fast, and repent. If therefore thou shalt not watch, I will come on thee as a thief, and thou shalt not know what hour I will come upon thee.

Because you have kept the word of My endurance [My command to persevere], I will keep you [safe] from the hour of trial, that hour which is about to come on the whole [inhabited] world, to test those who live on the earth.

Behold, I come quickly: hold that fast which thou hast, that no man take thy crown.

And after this I saw four angels standing upon the four corners of the earth, holding fast the four winds of the earth, that no wind might blow upon the earth, nor upon the sea, nor upon any tree.

This made the Dragon furiously angry with the woman, and he went elsewhere to make war upon her other children--those who keep God's commandments and hold fast to the testimony of Jesus.

Here is a call for the endurance of the saints, who keep the commandments of God and hold fast to their faithfulness in Jesus: