What Happens in Hharan, Stays in Hharan
An idea came to me today, which I don't remember seeing anywheres else before; probably because it isn't nearly as edifying as, for instance, the interpretation that it was really dark and Rahheil gave Lei’a her and Ya‘aqov's secret signals so that her sister wouldn't be ashamed.
Notice the sequence. First Lavan makes a big party. Then, later, he brings his daughter and gives her to Ya‘aqov. It may very well have been that in accordance with the term משתה, from the root 'drink', this was, as they say, an "open bar" wedding reception — before the wedding itself. Ya‘aqov Avinu could have been quite seriously and happily sloshed by the time his bride showed up; with this trick up his sleeve, Lavan would have made sure to ply him with as much alcohol as possible, in order to dull Ya‘aqov's senses enough so that he wouldn't notice the switch!
וַיַּעֲבֹד יַעֲקֹב בְּרָחֵל שֶׁבַע שָׁנִים, וַיִּהְיוּ בְעֵינָיו כְּיָמִים אֲחָדִים בְּאַהֲבָתוֹ אֹתָהּ. וַיֹּאמֶר יַעֲקֹב אֶל לָבָן, הָבָה אֶת אִשְׁתִּי — כִּי מָלְאוּ יָמָי, וְאָבוֹאָה אֵלֶיהָ. וַיֶּאֱסֹף לָבָן אֶת כָּל אַנְשֵׁי הַמָּקוֹם, וַיַּעַשׂ מִשְׁתֶּה. וַיְהִי בָעֶרֶב, וַיִּקַּח אֶת לֵאָה בִתּוֹ, וַיָּבֵא אֹתָהּ אֵלָיו; וַיָּבֹא אֵלֶיהָ. [...] וַיְהִי בַבֹּקֶר, וְהִנֵּה הִוא לֵאָה!...
And then Ya‘aqov worked for Rahheil seven years; but they were in his eyes as just a few days, in his love for her. And then Ya‘aqov said to Lavan, “Give me my wife — for my [contracted] days have been fulfilled, and I want to come to her.” And then Lavan gathered all the people of the place, and he made a drinking-party. And then it was in the evening, and he took Lei’a his daughter, and brought her to him [=Ya‘aqov]; and he [=Ya‘aqov] came to her. [...] And then it was in the morning, and hey, she was Lei’a!...
from Bereishit/Genesis 29:20-25
And then in the morning?
Oy what a headache. In many more ways than one.