Hayyim Vital, Liqqutim Hadashim I.

Jewish Mysticism
[The highest aspect of the soul] yehidah is from ’Arikh ’Anpin, and it is called yehidah, for from ’Arikh and below there is a female, but in ’Arikh ’Anpin there is no female but only male (’ein bo neqevah ki ’im dekhura’), and the reason is that from ’Imma’ and below there are judgments, and thus there is there a female for the female is the aspect of judgments. … Concerning him Scripture says, ‘Behold the eye of the Lord is upon those who fear him’ (Ps. 33-18). The explanation is that there are two eyes below, right and left, but he is mercy within mercy, and thus he is called ‘eye,’ for there is but one eye. Hence, it is called yehidah, for no female is there but only male (ki ’ein sham neqevah ki ’im zakhar), [and thus it] is called singular (yahid).

Translated by Elliot Wolfson, “Beyond Good and Evil- Hypernomianism, Transmorality, and Kabbalistic Ethics.” In, Crossing Boundaries- Ethics, Antinomianism and the History of Mysticism, pp. 103-56. Edited by J. J. Kripal and W. Barnard. New York and London- Seven Bridges Press, 2002, from Hayyim Vital, Liqqutim Hadashim, edited by Daniel Touitou (Jerusalem, 1985), 63.