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.”

2:7 head of the corner. The reference here is to Psalm 118:22, which in turn was referring to the tradition that, when Solomon’s temple was being built, the odd-shaped stone which seemed not to fit anywhere turned out to be the chief cornerstone, designed for the very apex of the temple. The stones had all been precisely cut deep in the quarry, so that no noise of construction could be heard while the temple was growing (see I Kings 5:17; 6:7). In analogous fashion, each believer is being laid quietly as a living stone in the great spiritual temple. But the unique stone of the pinnacle corner is Christ Himself, who is also the temple’s foundation. He is both underneath all, upholding us, and above all, crowning us as our glorious Head.

2:8 rock of offence. In the meantime, until He is made the head stone (Zechariah 4:7), Christ is just a stumbling stone on the ground, as it were, getting in the way of everyone who would pass by. Peter here quotes Isaiah 8:14, to which Jesus also referred in the same vein (Matthew 21:42-44). But note also Daniel 2:34 and Jeremiah 13:16.