Jamieson, Fausset and Brown on Song of Solomon 5:2

2. Sudden change of scene from evening to midnight, from a betrothal feast to cold repulse. He has gone from the feast alone; night is come; He knocks at the door of His espoused; she hears, but in sloth does not shake off half-conscious drowsiness; namely, the disciples' torpor (Mt 26:40-43), "the spirit willing, the flesh weak" (compare Ro 7:18-25; Ga 5:16, 17, 24). Not total sleep. The lamp was burning beside the slumbering wise virgin, but wanted trimming (Mt 25:5-7). It is His voice that rouses her (Jon 1:6; Ep 5:14; Re 3:20). Instead of bitter reproaches, He addresses her by the most endearing titles, "my sister, my love," &c. Compare His thought of Peter after the denial (Mr 16:7).

dew--which falls heavily in summer nights in the East (see Lu 9:58).

drops of the night--(Psa 22:2; Lu 22:44). His death is not expressed, as unsuitable to the allegory, a song of love and joy; So 5:4 refers to the scene in the judgment hall of Caiaphas, when Jesus Christ employed the cock-crowing and look of love to awaken Peter's sleeping conscience, so that his "bowels were moved" (Lu 22:61, 62); So 5:5, 6, the disciples with "myrrh," &c. (Lu 24:1, 5), seeking Jesus Christ in the tomb, but finding Him not, for He has "withdrawn Himself" (Joh 7:34; 13:33); So 5:7, the trials by watchmen extend through the whole night of His withdrawal from Gethsemane to the resurrection; they took off the "veil" of Peter's disguise; also, literally the linen cloth from the young man (Mr 14:51); So 5:8, the sympathy of friends (Lu 23:27).

undefiled--not polluted by spiritual adultery (Re 14:4; Jas 4:4).