Deuteronomy 17:6
4 When it is reported to you and you hear about it, you must investigate carefully. If it is indeed true that such a disgraceful thing is being done in Israel, 5 you must bring to your city gates that man or woman who has done this wicked thing—that very man or woman—and you must stone that person to death. 6 At the testimony of two or three witnesses the person must be executed. They cannot be put to death on the testimony of only one witness. 7 The witnesses must be first to begin the execution, and then all the people are to join in afterward. In this way you will purge the evil from among you. 8 If a matter is too difficult for you to judge—bloodshed, legal claim, or assault—matters of controversy in your villages—you must leave there and go up to the place the Lord your God chooses.
Hebrews 10:28
26 For if we deliberately keep on sinning after receiving the knowledge of the truth, no further sacrifice for sins is left for us, 27 but only a certain fearful expectation of judgment and a fury of fire that will consume God’s enemies. 28 Someone who rejected the law of Moses was put to death without mercy on the testimony of two or three witnesses. 29 How much greater punishment do you think that person deserves who has contempt for the Son of God, and profanes the blood of the covenant that made him holy, and insults the Spirit of grace? 30 For we know the one who said, “Vengeance is mine, I will repay,” and again, “The Lord will judge his people.”
Notes and References
"... Here perhaps is a good juncture to deal with the varied use of Deuteronomy in the book of Hebrews ... (Hebrews 1:6; Deuteronomy 32:43, Hebrews 10:28; Deuteronomy 17:6, Hebrews 12:3; Deuteronomy 32:35, Hebrews 12:15; Deuteronomy 29:17, Hebrews 12:18; Deuteronomy 4:11, Hebrews 12:21; Deuteronomy 9:19, Hebrews 12:29; Deuteronomy 4:24, Hebrews 13:5; Deuteronomy 31:6) ... Notice that all the quotations here are short, even fragmentary, and so Gert Steyn is right to ask: Is the author quoting from memory? And if so, should we be spending so much time trying to figure out which version of the OT he is using, when he could be paraphrasing in his own language? Importantly, Steyn points out that unlike his Psalms and Jeremiah quotations, the use of Deuteronomy does not involve extended quotations, nor are the Deuteronomy quotations cited with reference to divine authority. Could this be because our author, while recognizing Deuteronomy as Scripture believes the Mosaic covenant is no longer binding on his audience per se, and particularly because he doesn’t want these Jewish Christians retreating back into non-Christian Judaism under pressure or persecution is being careful how he uses the Law? In any case, he clearly believes the Mosaic covenant has been superseded by a better covenant, the new covenant. Further, what explains the fact that apart from Hebrews 1:6, all of the citations come between Hebrews 10:28 and 13:5? Even of these nine found within those parameters, only four are clearly explicit quotations, Deuteronomy 32:43 (LXX Ode 2) in Hebrews 1:6; Deuteronomy 32:35–36 in Hebrews 10:30–31; Deuteronomy 9:19 in Hebrews 12:21; and Deuteronomy 31:6 in Hebrews 13:5 ..."
Witherington, Ben Torah Old and New: Exegesis, Intertextuality, and Hermeneutics (p. 328) Fortress Press, 2018