Midrash holds that the children of Israel fell asleep on the cusp of the revelation of Torah. This is the reason usually given for the custom of the tikkun leyl Shavuot, the late-night or all-night study session whose name means "healing on the eve of Shavuot." The healing needed is a kind of spiritual rectification, a chance to make up for our own mistake. When we stay up late studying Torah, we are saying to God (and to ourselves) that revelation matters to us; that we want to be open to the Torah which is coming. We don't want to oversleep this time.
Curiously, the midrash also tells us that God was pleased with the Israelites, and ensured that no mosquitoes bit them that night, so they could enjoy a deep and restful slumber. Perhaps, as the author of Angels, human beings, and the Torah argues, they went to sleep because they knew they couldn't grasp the full meaning of Torah with their conscious minds. They wanted to receive revelation in their dreams. And God got that; God was pleased! But God still asked Moshe to wake them up so that Torah could be given to people who were spiritually (and physically) awake.
In the Hasidic understanding, the Torah which we know in this world is a physical manifestation of -- and also a pale reflection of -- the supernal Torah which is known to God on high. Bereshit Rabbah (a classical commentary on Genesis) teaches us that when a person sleeps, a portion of their soul ascends on high and is united with God; upon waking, the soul returns to the body. Who can know what Torah was revealed to our ancestors in that holy sleep? Their souls (or, as another midrash has it, our souls -- since we all stood at Sinai, every Jewish soul which has ever been or will ever be) ascended on high and connected with God. And then they woke up, and received revelation in a different way.
I've long loved the custom of the tikkun leyl Shavuot. Late at night, the world feels different. I can believe that revelation takes a unique form in the wee hours of the night. When I used to stay up all night for fun in college, I relished both the silliness and the philosophical insights which arose at, say, three a.m. When I did my year of hospital chaplaincy, many years later, I found that some of my deepest and most meaningful encounters took place in the wee hours. Maybe we're more vulnerable in the middle of the night. Maybe we're open to things in a way which is different than the ordinary waking day.
Of course, since Drew was born, I don't stay up so late anymore. (Indeed: he's two and a half and I still haven't shaken the habit, learned during his first year, of keeping jealous track of my hours of sleep. When I wake in the night, I can't help counting how much sleep I've managed and how much I know I still need in order to function in the new day.) I've learned since having a child that sleep is a precious commodity, not necessarily replaceable, and that when I don't have it, I don't function well.
And yet, come Shavuot -- come Shavuot, I offer God my wakefulness until the darkest hours of the night, two and three and some years even four. Over the years, I've come to see the tikkun leyl Shavuot as a mysterious blend of waking-consciousness and dream-consciousness. My body is awake and I am giving myself to the experience of Torah study: in that sense, I'm repairing the mistake made at the night before Sinai. But after a while I'm not exactly awake -- not awake in the same way as during the ordinary daytime, anyway. Who knows what the revelations may come when I'm in that strange spacey middle-of-the-night headspace and heartspace? Once a year, I have a date with God; I can lose a little sleep for that.
Still, I can't help being struck by the mixed messages in the midrash. On the one hand, God kept the mosquitoes from biting on the eve of the theophany at Sinai. God wanted to ease our sleep, to help our souls reach the deep Torah which can be accessed not with the waking mind but with dreaming consciousness. And on the other hand, God told Moshe to wake us up (and our central holiday practice is one of attempting to "heal" our error in oversleeping.) Because the spiritual, heady, dreamy aspects of Torah which we can access while we're sleeping are only part of the revelation. The other part -- perhaps the practical tangible part, the this-worldly part -- has to happen while we're awake.
This is one of the reasons I love teaching Torah poetry in the middle of the night at Shavuot. Poetry can function on levels beyond the purely intellectual. Like dreams, poems often work associatively. They recast ideas and images in new ways. Reading Torah poetry in the middle of the night feels a bit like a waking dream -- a chance to fulfil both the mitzvah of staying awake for Shavuot, and the mitzvah of opening ourselves up to the revelations in our dreams.