corner: the angle where two lines, walls, streets, or edges meet
This is the plain, everyday Greek word for a corner, the place where two lines or two surfaces come together at an angle. It named the corner of a street, of a house, or of a plot of land, and it was also the standard word Greek mathematicians used for an angle in geometry. Our English "polygon" and "diagonal" descend from it. There is nothing technical or religious about the word itself.
What gives it force is what it is the corner of:
- Out on the street, a corner is where everyone can see you (Matthew 6:5).
- Tucked away indoors, a corner is where nobody can see you, so doing something "in a corner" meant doing it out of public view (Acts 26:26).
- Stretched to the whole world, the corners are its far edges, four points that together mean everywhere (Revelation 7:1).
- On a building, the corner is the one spot that fixes how the walls line up, so the stone that holds it governs the whole structure.
That last use carries most of the weight in the New Testament. Five of the word's nine appearances sit inside one quoted line from Psalm 118: the stone the builders threw away has become "the head of the corner." Behind the Greek stands the Hebrew word for corner (פִּנָּה), which could also name the leading men of a people, the ones who hold a nation together the way corner stones hold up a building. That figure of speech is part of why the rejected stone of the psalm was read as a person. Applying the line to Jesus says two things at once: he was thrown out by the very people who were supposed to be building God's house, and God then set him in the place everything else is measured by.
Exactly which stone the picture shows is an old argument. The phrase, and the related word for a stone at the far corner (ἀκρογωνιαῖος), may mean the great squared block laid at the base corner, which sets the line of every wall above it, or the final stone set high up that locks the whole building together. Most scholars now favor the base corner, chiefly because the Greek Old Testament verse that supplies the word puts the stone down in the foundations (θεμέλιος). Either way the point holds: the entire building depends on this one stone.
Nuances
Disputed
Whether the stone named by the corner phrase of Psalm 118:22 (κεφαλὴ γωνίας) and by the cognate adjective of Isaiah 28:16 (ἀκρογωνιαῖος) is the block set at the base corner of a building or the final stone that crowns it.
- majorityA foundation cornerstone: the large squared block at the base corner that joins two walls and fixes the alignment of the whole structure. The decisive supports are that the sole Septuagint occurrence of ἀκρογωνιαῖος (Isaiah 28:16) places the stone εἰς τὰ θεμέλια Σιων, that the Qumran reception of Isaiah 28:16 (1QS 8:7-8) reads a foundation image, and that ἄκρος intensifies rather than relocates γωνιαῖος.; R. J. McKelvey, "Christ the Cornerstone," New Testament Studies 8/4 (1962), 352-359; R. J. McKelvey, The New Temple: The Church in the New Testament (Oxford University Press, 1969); Harold W. Hoehner, Ephesians: An Exegetical Commentary (Baker Academic, 2002), 404-407; Peter T. O'Brien, The Letter to the Ephesians, PNTC (Eerdmans, 1999), 216-218; Clinton E. Arnold, Ephesians, ZECNT (Zondervan, 2010), 170-171
- minorityA capstone or topstone (Schlussstein): the final crowning stone set high over the gate, which completes and locks the structure and suits the Pauline emphasis on Christ as head. The supports are the Testament of Solomon 22:7-23:4, Symmachus at 2 Kings 25:17, and the force of κεφαλή in the psalm phrase.; Joachim Jeremias, "Κεφαλὴ γωνίας, Ἀκρογωνιαῖος," Zeitschrift für die neutestamentliche Wissenschaft 29 (1930), 264-280; Joachim Jeremias, "γωνία, ἀκρογωνιαῖος," in Theological Dictionary of the New Testament, ed. Gerhard Kittel, 1:792-793; Markus Barth, Ephesians 1-3, Anchor Bible 34 (Doubleday, 1974), 317-319; Andrew T. Lincoln, Ephesians, WBC 42 (Word, 1990), 154-156
- minorityDeliberately open: the term is best rendered by a neutral "angle-stone," and in Ephesians 2:20 the author may have chosen it precisely because it can carry both pictures at once.; Ernest Best, A Critical and Exegetical Commentary on Ephesians, ICC (T&T Clark, 1998), 284-286; Frank Thielman, Ephesians, BECNT (Baker Academic, 2010), 182