Bible: Hold Fast Is

Repeated words found across different books in the Bible (KJV):
2Ki 6:32
But Elisha sat in his house, and the elders sat with him; and the king sent a man from before him: but ere the messenger came to him, he said to the elders, See ye how this son of a murderer hath sent to take away mine head? look, when the messenger cometh, shut the door, and hold him fast at the door: is not the sound of his master's feet behind him?

Prv 4:13
Take fast hold of instruction; let her not go: keep her; for she is thy life.

Jer 8:5
Why then is this people of Jerusalem slidden back by a perpetual backsliding? they hold fast deceit, they refuse to return.

Mat 26:48
Now he that betrayed him gave them a sign, saying, Whomsoever I shall kiss, that same is he: hold him fast.

1Th 5:21
Prove all things; hold fast that which is good.

2Tim 1:13
Hold fast the form of sound words, which thou hast heard of me, in faith and love which is in Christ Jesus.

Heb 4:14
Seeing then that we have a great high priest, that is passed into the heavens, Jesus the Son of God, let us hold fast our profession.

Heb 10:23
Let us hold fast the profession of our faith without wavering; (for he is faithful that promised;)