The Messiah as the Corner Stone
We can best end this lecture with a consideration of the three prophecies of the corner or topstone, viz. Is. xxviii. 16, Zc. iii. 9, iv. 7, Ps. cxviii. 22. It is of course incapable of mathematical proof that the three passages are connected, but the strong impression created by the second and third that a definitely known stone is under consideration makes such a connection highly probable.
We are first introduced to the stone in Isaiah when the scornful rulers of Jerusalem with their self-chosen and self-confident foreign policy are confronted with a stone laid by Yahweh in Zion. Their building is to be swept away by the coming storm but the stone will abide. It is called an ebhenbochan, which is in the English versions rendered 'a tried stone' (A.V., R.V., R.S.V., Moffatt). But as Delitzsch points out bochan is active and means testing. Brown, Driver, Briggs in their Lexicon agree, but in spite of that give it a passive meaning. The fact is that it is a testing stone. Isaiah never speaks of its being built on. It is a pledge of safety to those that believe in the day that 'the shelter of lies' is swept away.
This stone rejected by the builders, the rulers of the people, appears again in Zechariah, after the exile caused by the false building of the pre-exilic rulers. We now find that it is a headstone or a topstone. This is a stone cut beforehand by the architect, which not only, as the last stone to be dropped into place, bonds the building together, but also by whether it fits or not tests whether the architect's plans have been truly followed. We are not called on to judge how truly Zerubbabel built for his day and generation, for in 'Ps. cxviii we find the fulfilment expressed in the prophetic perfect but none the less future, for the Psalm is clearly Messianic.
Even so it is with Jesus Christ. The various forms of Messianic prophecy knit together divergent lines of Old Testament thought and mould them into a pattern whose final form may not be clear but which can yet be inferred. Bring the fulfilment in Christ and drop it into place as the topstone and the house is complete in all its portions and proportions.
For the one who will work or expound without thought of God's Messiah, the testing stone has been laid by God there in Zion. He will not be able to avoid it, and 'he that falleth on this stone shall be broken to pieces' (Mt. xxi. 44). There is, however, a worse fate foretold for the man who in theory accepts the testing stone, but in practice works and expounds led by his own wisdom and will. When the topstone is hoisted to its place on the summit of his building, it will come crashing down and 'on whomsoever it shall fall, it will scatter him as dust'.
Questions for Reflection / Discussion:
Read Isaiah 28:16, Zechariah 3:9, 4:7, and Psalm 118:22 (paying attention to surrounding context). What sort of role does teh stone play in each of these passages?
What do you make of the idea that Ellison describes of Jesus as the 'topstone', cut before hand by the architect, that brings together all the disparate pieces of the building? Do you find this helpful for thinking about the way that Jesus brings together the threads of 'Messiahship' from the Old Testament?
In what ways might Jesus be a stumbling block or a stone that crushes in this context?
Reflecting on the series as a whole, how has this overview of 'Messiahship' affected your view of the Old Testament? Of Jesus?
 Koehler's derivation from Egyptian seems dubious.
 For a fuller exposition see articles by B. E. Le Bas in Palestine Exploration Quarterly, July-Oct.1946, July-Oct. 1950, July-Oct. 1951.