Thou hast ravished my heart, my sister, my spouse; thou hast ravished my heart with one of thine eyes, with one chain of thy neck. Thou hast ravished my heart - לבבתני libbabtini, "Thou hast hearted me," i.e., taken away my heart; as we say, "He has barked the tree," i.e., he has stripped it of its bark; "He has fleeced the flock," i.e., deprived them of their wool.
With one of thine eyes - באצד מעיניך beachad meeynayich. This has been thought a harsh expression, and various emendations have been sought. The Masoretes have put באצת beachath, "at once," in the margin; and this is confirmed by twenty of Kennicott's MSS. but De Rossi does not notice it. It is scarceiy necessary; the sense to me is clear and good without it. "Even one of thine eyes, or one glance of thine eyes, has been sufficient to deprive me of all power; it has completely overcome me;" for glance may be understood, and such forms of speech are common in all languages, when speaking on such subjects. If even taken literally, the sense is good; for the poet may refer to a side glance, shot in passing by or turning away, where only one eye could be seen. I think this a better sense than that which is obtained from the Masoretic emendation.
With one chain of thy neck - Probably referring to the play of the cervical muscles, rather than to necklaces, or ringlets of hair.