Isaiah 62:5 (ESV) … “For as a young man marries a young woman, so shall your sons marry you, and as the bridegroom rejoices over the bride, so shall your God rejoice over you.”
By means of a comparison Isaiah confirms what has just been stated. The introductory ki is not the particle of comparison (which is omitted) but is to be translated For.
Difficulty has been found in the thought of sons marrying a mother, but the difficulty is resolved if the connotation of possess be noted. As a young man marries a virgin, so the sons of Zion, through God’s grace, will occupy and possess her. She will then no longer be desolate and forsaken but filled with her spiritual sons. As the bride of the Lord, Zion will also be recognized, and He will rejoice in her as an earthly bridegroom rejoices in his bride. The figure is designed to express the utmost of rejoicing. Rejoicing is an inner accusative; and with the rejoicing of a bridegroom, etc. When God receives the Church as His bride and rejoices at the multitude of her sons, then truly the Church is blessed.
The restoration of Israel will result in pleasure for God which is a contrast to how disappointed many anti-Israeli people will be when they see the people they despised being exalted and honored.
There is a wedding day in prospect, but, as always, God’s promises are given to encourage persevering prayer. And that’s what Isaiah commits himself to. When the wedding day finally arrives there will be a change of name for the bride, reflecting a change of fortunes. Or perhaps ‘reversal of fortunes’ would be more accurate. The time when God’s people appeared forsaken and their land was left desolate will come to an end. Instead, the Lord’s delight in his people and care for their land will once again be evident (62:1–5).
 Young, E. (1972). The Book of Isaiah, Chapters 40–66 (Vol. 3, pp. 469–470). Grand Rapids, MI: Wm. B. Eerdmans Publishing Co.  Butler, J. G. (2013). Isaiah to Ezekiel (Vol. 8, pp. 354–355). Clinton, IA: LBC Publications.  Thomson, A. (2012). Opening Up Isaiah (p. 148). Leominster: Day One.