C. F. Keil and Franz Delitzsch on Song of Solomon 3:1

Sol 3:1 1 On my bed in the nights    I sought him whom my soul loveth:    I sought him, and found him not.

She does not mean to say that she sought him beside herself on her couch; for how could that be of the modest one, whose home-bringing is first described in the next act - she could and might miss him there neither waking nor sleeping. The commencement is like Job 33:15. She was at night on her couch, when a painful longing seized her: the beloved of her soul appeared to have forsaken her, to have withdrawn from her; she had lost the feeling of his nearness, and was not able to recover it. לילות is neither here nor at Sol 3:8 necessarily the categ. plur. The meaning may also be, that this pain, arising from a sense of being forgotten, always returned upon her for several nights through: she became distrustful of his fidelity; but the more she apprehended that she was no longer loved, the more ardent became her longing, and she arose to seek for him who had disappeared.