Jeremiah 9:26
24 If people want to boast, they should boast about this: They should boast that they understand and know me. They should boast that they know and understand that I, the Lord, act out of faithfulness, fairness, and justice in the earth and that I desire people to do these things,” says the Lord. 25 The Lord says, “Watch out! The time is soon coming when I will punish all those who are circumcised only in the flesh. 26 That is, I will punish the Egyptians, the Judeans, the Edomites, the Ammonites, the Moabites, and all the desert people who cut their hair short at the temples. I will do so because none of the people of those nations are really circumcised in the Lord’s sight. Moreover, none of the people of Israel are circumcised when it comes to their hearts.”
Acts 7:51
49 ‘Heaven is my throne, and earth is the footstool for my feet. What kind of house will you build for me, says the Lord, or what is my resting place? 50 Did my hand not make all these things?’ 51 “You stubborn people, with uncircumcised hearts and ears! You are always resisting the Holy Spirit, like your ancestors did! 52 Which of the prophets did your ancestors not persecute? They killed those who foretold long ago the coming of the Righteous One, whose betrayers and murderers you have now become! 53 You received the law by decrees given by angels, but you did not obey it.”
Notes and References
"... Fast-forwarding to Acts 7:51 where we finally have the direct accusation by Stephen against his audience, calling them a “stiff-necked” people, and so like the wilderness wandering generation (compare the application to rebelling Israelites in Exodus 33:3, 5; 34:9; Deuteronomy 9:6, 13; see also Baruch 2:30). Then there is the phrase “uncircumcised in heart and ears”, which owes something to Leviticus 26:41; Jeremiah 9:26; and Ezekiel 44:7, 9 (the “ears” part coming from Jeremiah 6:10). This very same sort of phrasing used to critique recalcitrant Jews is found at Qumran (1QS V, 5; 1 QpHab XI, 13; Jubilees 1:7, 23). This then is not a Christian polemic against Judaism, but rather an in-house critique by one group of sectarian Jews of another. The same must be said of the accusation in 7:52 about them being prophet-killers, a common theme (1 Kings 19:10, 14; 2 Chronicles 36:16; Nehemiah 9:26; Jeremiah 26:20–24) further amplified in the New Testament, especially in the Gospels (see especially Matthew 23:29–36) ..."
Witherington, Ben Torah Old and New: Exegesis, Intertextuality, and Hermeneutics (pp. 174-175) Fortress Press, 2018