Proverbs 30:6
4 Who has ascended into heaven, and then descended? Who has gathered up the winds in his fists? Who has bound up the waters in his cloak? Who has established all the ends of the earth? What is his name, and what is his son’s name? Surely you can know! 5 Every word of God is purified; he is like a shield for those who take refuge in him. 6 Do not add to his words, lest he reprove you and prove you to be a liar. 7 Two things I have asked from you; do not refuse me before I die: 8 Remove falsehood and lies far from me; do not give me poverty or riches; feed me with my allotted portion of bread,
Revelation 22:18
16 “I, Jesus, have sent my angel to testify to you about these things for the churches. I am the root and the descendant of David, the bright morning star!” 17 And the Spirit and the bride say, “Come!” And let the one who hears say: “Come!” And let the one who is thirsty come; let the one who wants it take the water of life free of charge. 18 I testify to everyone who hears the words of the prophecy contained in this book: If anyone adds to them, God will add to him the plagues described in this book. 19 And if anyone takes away from the words of this book of prophecy, God will take away his share in the tree of life and in the holy city that are described in this book. 20 The one who testifies to these things says, “Yes, I am coming soon!” Amen! Come, Lord Jesus!
Notes and References
"... John now turns abruptly to a serious threat ... The word translated warn means “witness” or “testify” (verses 16, 20; 1:2); Hughes suggests that it is the obverse of “blessed” (1990:240: 1:3; 22:7). The plagues are the bowl judgments. Hence, the punishment fits the offense; the person who tampers with the prophecy receives the judgment of the same prophecy. This warning has roots in a variety of biblical passages (Deuteronomy 4:2; 12:32; 29:19-20; Proverbs 30:6; Galatians 1:6-9; 1 Enoch 104:10; 2 Enoch 48:7-8). Moreover, in days before the printing press and copyright laws, it was common to end a letter with a warning against tampering with its message. The problem is illustrated by Tertullian, who accused Valentinus of perverting his text with additions and alterations (Against Heresies 38) ..."
Yeatts, John R. Revelation (p. 421) Herald Press, 2003