John Gill's Exposition of the Whole Bible
Song of Solomon 6:9
My dove, my undefiled, is [but] one,.... Of these titles, see Song of Solomon 2:14. Christ's church is called one, in distinction from the many before mentioned; and either designs her small number, in comparison of the nations of the world, and of false churches, like one to sixty or eighty, and even to an innumerable company; see Ecclesiastes 9:14
Luke 12:32; or else her unity in herself, being but one general assembly and church of the firstborn, made up of various particular congregated churches; and "one body", consisting of various members, united together in affection, and partakers of the same grace, blessings, and privileges; actuated by "one Spirit", the Spirit of God, Ephesians 4:4; and having but "one Head", Christ Jesus, Ephesians 4:15: and it may signify that the church is the spouse of Christ; that though other princes may have sixty queens, and eighty concubines, and virgins without number, to wait on them, Song of Solomon 6:8; Christ had but one, and was well pleased with her, and desired no other;
she [is] the [only] one of her mother; the Jerusalem above, the mother of us all: or the sense is, she was to Christ as a mother's only child, most tenderly beloved by him;
she [is] the choice one of her that bare her; esteemed and loved best of all her mother's children. The word may be rendered, "the pure" or "clean one" l; so the church is, as clothed in "clean" linen, the righteousness of Christ; cleansed from sin in his blood; sprinkled with the clean water of the covenant, and of an unspotted conversation.
The daughters saw her, and blessed her; [yea], the queens and the concubines, and they praised her: it may seem strange that concubines should praise a queen; but it was not unusual in the eastern countries; with the Persians, as the queen admitted of many concubines by the order of her lord the king, so the queen was had in great veneration, and even adored by the concubines m: which may respect either the great esteem the church had, or should have, in the world, even from the great men of it, as she will have in the latter day,
Isaiah 49:23; or which young converts have for her; who may more especially be meant by the "daughters" and "virgins", who, in Song of Solomon 6:1, call the church the "fairest among women": these blessed her, and pronounced her happy, and wished all happiness to her; they "praised her", spoke well of her, and commended her for her beauty; which was pleasing to Christ, and therefore observed by him.
l ברה "munda", Montanus, Mercerus; "pura", Vatablus, Junius Tremellius, Piscator, Cocceius, Marckius, Michaelis. m Dinon in Persicis apud Athenaei Deipnosoph. l. 13. c. 1. p. 556.