How is it possible that Yaakov didn’t know he spent his wedding night with Leah rather than Rachel? The text says, “and it came to pass in the morning and behold it was Leah” (Genesis 29:25).
Some commentators suggest this reveals the extraordinary modesty of Yaakov and Leah – all through the night they did not see or even speak to each other (Radak).
The Talmud explains that Yaakov could have been fooled in another way. Suspecting that Lavan would switch Leah for Rachel, Yaakov gave Rachel signs through which she could identify herself to him. When at the last moment Lavan indeed exchanged Leah for Rachel, Rachel feared Leah would be embarrassed and gave her sister the special signs (Megillah 13b).
But all this leads to another question. If in fact Yaakov didn’t know it was Leah, how could the marriage have been legitimate? Isn’t this a classic case of an agreement that is considered null and void because of faulty assumptions, known as mekah ta’ut?
Perhaps it can be said that Yaakov’s surprise came that evening, yet he still accepted Leah as his wife. When the text indicates that on the next morning “behold, it was Leah,” it is the community that learned of the switch.
Outside of these attempts to understand Yaakov’s being fooled, there is a kabbalistic approach. This approach teaches something fundamental about love. Rachel represents the woman Yaakov wished to marry. But it is often the case that once married, we find elements in our spouse’s personality of which we were previously unaware. These unknown factors are represented by Leah. In any relationship, there will be pieces of our partner’s personality that take us by surprise.
These elements may be distasteful. In such a case, the challenge is to make peace with that side of our beloved and realize that love means accepting the whole person. But it can be that this hidden side is a positive one that never formerly surfaced. These traits have the capacity to add vibrancy and a new excitement to the relationship. At times these new qualities can even turn out to be exactly what was always needed.
“And behold it was Leah” teaches that in every relationship there will always be an element of surprise, the element we don’t consciously choose, the element represented by Leah.