'Because of his strength will I wait upon Thee: for God is my defence.... 17. Unto Thee, O my strength, will I sing: for God is my defence, and the God of my mercy.'--PSALM lix. 9, 17. There is an obvious correspondence between these two verses even as they stand in our translation, and still more obviously in the Hebrew. You observe that in the former verse the words 'because of' are a supplement inserted by our translators, because they did not exactly know what to make of the bare words as they stood. 'His strength, I will wait upon Thee,' is, of course, nonsense; but a very slight alteration of a single letter, which has the sanction of several good authorities, both in manuscripts and translations, gives an appropriate and beautiful meaning, and brings the two verses into complete verbal correspondence. Suppose we read, 'My strength,' instead of 'His strength.' The change is only making the limb of one letter a little shorter, and as you will perceive, we thereby get the same expressions in both verses. We may then read our two texts thus: 'Upon Thee, O my Strength! I will wait.... Unto Thee, O my Strength, I will sing!' They are, word for word, parallel, with the significant difference that the waiting in the one passes into song, in the other, the silent expectation breaks into music of praise. And these two words--_wait_ and _sing_--are in the Hebrew the same in every letter but one, thus strengthening the impression of likeness as well as emphasising, with poetic art, that of difference. The parallel, too, obviously extends to the second half of each verse, where the reason for both the waiting and the praise is the same--'For God is my defence'--with the further eloquent variation that the song is built not only on the thought that 'God is my defence,' but also on this, that He is 'the God of my mercy.' These two parallel verses, then, are a kind of refrain, coming in at the close of each division of the psalm; and if you examine its structure and general course of thought, you will see that the first stands at the end of a picture of the Psalmist's trouble and danger, and makes the transition to the second part, which is mainly a prayer for deliverance, and finishes with the refrain altered and enlarged, as I have pointed out.