Sing, O barren, thou that didst not bear "Shout for joy, O thou barren, that didst not bear" - The Church of God under the Old Testament, confined within the narrow bounds of the Jewish nation, and still more so in respect of the very small number of true believers, and which sometimes seemed to be deserted of God her husband, is the barren woman, that did not bear, and was desolate. She is exhorted to rejoice, and to express her joy in the strongest manner, on the reconciliation of her husband, (see Isaiah 54:6), and on the accession of the Gentiles to her family. The converted Gentiles are all along considered by the prophet as a new accession of adopted children, admitted into the original Church of God, and united with it. See Isaiah 49:20, Isaiah 49:21.

Isaiah 33:20 Look on Zion, the city of our solemnities: your eyes shall see Jerusalem a quiet habitation, a tabernacle that shall not be taken down...

Isaiah 49:19,20 For your waste and your desolate places, and the land of your destruction, shall even now be too narrow by reason of the inhabitants...

Jeremiah 10:20 My tabernacle is spoiled, and all my cords are broken: my children are gone forth of me, and they are not...

Manner of Covenanting.
Previous to an examination of the manner of engaging in the exercise of Covenanting, the consideration of God's procedure towards his people while performing the service seems to claim regard. Of the manner in which the great Supreme as God acts, as well as of Himself, our knowledge is limited. Yet though even of the effects on creatures of His doings we know little, we have reason to rejoice that, in His word He has informed us, and in His providence illustrated by that word, he has given us to …
John Cunningham—The Ordinance of Covenanting

How the Impudent and Bashful are to be Admonished.
(Admonition 8). Differently to be admonished are the impudent and the bashful. For those nothing but hard rebuke restrains from the vice of impudence; while these for the most part a modest exhortation disposes to amendment. Those do not know that they are in fault, unless they be rebuked even by many; to these it usually suffices for their conversion that the teacher at least gently reminds them of their evil deeds. For those one best corrects who reprehends them by direct invective; but to …
Leo the Great—Writings of Leo the Great

Messiah the Son of God
For to which of the angels said He at any time, Thou art My Son, this day have I begotten Thee? T hough every part of a revelation from God must of course be equally true, there may be a considerable difference even among truths proposed by the same authority, with respect to their immediate importance. There are fundamental truths, the knowledge of which are essentially necessary to our peace and holiness: and there are others of a secondary nature, which, though very useful in their proper connection, …
John Newton—Messiah Vol. 2