John Gill Commentary Isaiah 49:18

"Lift up thine eyes round about, and behold: all these gather themselves together, and come to thee. As I live, saith Jehovah, thou shalt surely clothe thee with them all as with an ornament, and gird thyself with them, like a bride." — Isaiah 49:18 (ASV)

Lift up your eyes round about, and behold
Look east, west, north, and south, and behold the flocking converts from all parts; see on (Isaiah 49:12). The words are spoken to the church, and for her comfort; and so the Targum, "lift up your eyes round about, O Jerusalem, and see all the children of the people of your captivity:"

all these gather themselves together, and come to you ;
though of different nations, and come from different quarters, yet coalesce together, make one body, and join themselves with the church, in which they centre, and are incorporated:

as I live, says the Lord ;
this is the form of an oath, sometimes used by the Lord, to denote the importance and certainty of a thing, and to assure his people of it:

you shall surely clothe you with them all as with an ornament; as
children's children are the crown of old men ,
(Proverbs 17:6) , so young converts are the crown, glory, and ornament of the church; even such who are beautified with the graces of the Spirit, and whose conversations are as become the Gospel of Christ:

and bind them on you as a bride does ;
her clothes, the attire of her head, and her jewels. So in the latter day, when the Jews are converted, and the fulness of the Gentiles brought in, the marriage of the Lamb will be come, and the church made ready, as a bride, for her husband, and be very beautiful and comely in his sight, as well as very comfortable and glorious in herself; and which will be matter of joy to all the saints, (Revelation 19:7Revelation 19:8). The Targum is, "all these shall be unto you as a garment of glory, and their works in the midst of you as the ornament of a bride."