Pro 30:1 The words of Agur the son of Jakeh, even the prophecy: the man spake unto Ithiel, even unto Ithiel and Ucal,
Pro 30:2 Surely I am more brutish than any man, and have not the understanding of a man.
Pro 30:3 I neither learned wisdom, nor have the knowledge of the holy.
Pro 30:4 Who hath ascended up into heaven, or descended? who hath gathered the wind in his fists? who hath bound the waters in a garment? who hath established all the ends of the earth? what is his name, and what is his son’s name, if thou canst tell?
Pro 30:5 Every word of God is pure: he is a shield unto them that put their trust in him.
Pro 30:6 Add thou not unto his words, lest he reprove thee, and thou be found a liar.
There are some powerful words in the NT confirming this doctrine,
2Ti 3:15 And that from a child thou hast known the holy scriptures, which are able to make thee wise unto salvation through faith which is in Christ Jesus.
2Ti 3:16 All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness:
2Ti 3:17 That the man of God may be perfect, throughly furnished unto all good works.
Mat 5:17 Think not that I am come to destroy the law, or the prophets: I am not come to destroy, but to fulfil.
Mat 5:18 For verily I say unto you, Till heaven and earth pass, one jot or one tittle shall in no wise pass from the law, till all be fulfilled.
Mat 5:19 Whosoever therefore shall break one of these least commandments, and shall teach men so, he shall be called the least in the kingdom of heaven: but whosoever shall do and teach them, the same shall be called great in the kingdom of heaven.
Mat 5:20 For I say unto you, That except your righteousness shall exceed the righteousness of the scribes and Pharisees, ye shall in no case enter into the kingdom of heaven.
Rev 22:16 I Jesus have sent mine angel to testify unto you these things in the churches. I am the root and the offspring of David, and the bright and morning star.
Rev 22:17 And the Spirit and the bride say, Come. And let him that heareth say, Come. And let him that is athirst come. And whosoever will, let him take the water of life freely.
Rev 22:18 For I testify unto every man that heareth the words of the prophecy of this book, If any man shall add unto these things, God shall add unto him the plagues that are written in this book:
Rev 22:19 And if any man shall take away from the words of the book of this prophecy, God shall take away his part out of the book of life, and out of the holy city, and from the things which are written in this book.
Rev 22:20 He which testifieth these things saith, Surely I come quickly. Amen. Even so, come, Lord Jesus.