Genesis 29:
Dr. Constable's Expository Notes:21 Then Jacob said to Laban, “Give me my wife that I may go in to her, for my time is completed.” 22So Laban gathered together all the people of the place and made a feast. 23But in the evening he took his daughter Leah and brought her to Jacob, and he went in to her. 24(Laban gaveb his female servant Zilpah to his daughter Leah to be her servant.) 25And in the morning, behold, it was Leah! And Jacob said to Laban, “What is this you have done to me? Did I not serve with you for Rachel? Why then have you deceived me?”
Gill's Exposition of the Whole Bible:Jacob had pretended to be his older brother, and now Leah pretended to be her younger sister. Laban and Leah deceived Jacob as Jacob and Rebekah had deceived Isaac. Perhaps Jacob’s eating and drinking at the feast had clouded his mind (Genesis 29:22). The darkness of his tent at night may have made it hard for him to see, too. [Note: Josephus, 1:19:6-7.] Furthermore, in that culture a bride customarily entered her husband’s presence veiled. [Note: S. R. Driver, Genesis, p. 271.] Von Rad wrote "heavily veiled," and Aalders "completely veiled." [Note: Von Rad, p. 291; Aalders, p. 115.] One year an Indian student of mine told me that his father did not see his mother’s face for three days after their wedding. It is still customary among some Indians for the bride to remain veiled even after the consummation of the marriage. [Note: See also J. A. Diamond, "The Deception of Jacob: A New Perspective on an Ancient Solution to the Problem," Vetus Testamentum 34:2 (April 1984):211-13.]
If you think Jacob was having a confusing night, try this real-life story of a guy having sex with a man that he thought was a woman over and over again :)And it came to pass, that, in the morning, behold, it [was] Leah. The morning light discovered her, and her veil being off, her tender eyes showed who she was: it is much her voice had not betrayed her; but perhaps there might be a likeness of voice in her and her sister; or she might keep silence, and so not be discovered in that way.