New Defender's Study Bible Notes
2:6 chief corner stone. Note that Peter here recognizes that Christ, not himself, is the foundation stone of the church (as some have misinterpreted the teaching of Matthew 16:18). He is quoting from Isaiah 28:16, showing that this Messianic prophecy was fulfilled in Christ. The Lord Jesus also called His words the true foundation (Matthew 7:24-27) and Paul confirmed that there is no other foundation (I Corinthians 3:11). Isaiah had also stressed that “in the LORD JEHOVAH is everlasting strength,” or “the Rock of ages” (Isaiah 26:4).
2:6 be confounded. “Make haste” in Isaiah 28:16 is interpreted by Peter as “be confounded,” meaning “be ashamed.”