Leviticus Rabbah 26:4
"And the Lord said to Moses: Speak to the priests . . . " This bears on what Scripture says: "Day unto day utters speech" (Psalm 19:3). It was taught: on the day of the tekufah of Nisan and on the first day of the tekufah of Tishrei the day and the night are equal. From then onwards the day borrows from the night and the night from the day, and they repay each other amicably, everything being done without legal document or judicial verdict. This explains "day unto day utters speech." Here below, however, what a multitude of legal documents and what a multitude of judicial verdicts are required!
A midrash for any attorney or accountant to love, the last line of which already rings with the oy vey iz mir tone which has come down to us via Tevye and Seinfeld as a quintessentially Jewish mode of wry humor.
If ever one needed evidence that Judaism idealizes nature, here it is. We "down below" on earth are stuck with mounds of paperwork every time we need to lend or borrow from anyone, but in nature things are not so complicated. The spring and fall equinoxes (two of four astronomical tekufot, circuits, as designated by the rabbis) are seen as moments of natural balance, where night and day share equally. The rest of the year is an "amicable" give-and-take, a conversation in which day and night lend to and borrow from one another. Psalm 19—which we recite on Shabbat and festival mornings—alludes to this peaceful state of nature, the turning from one day to the next, via a night that does not complain or harass itself into the Psalm and that gives freely to its daytime partner, knowing it will receive with equal generosity when winter comes.
The midrash is playful and wise, and as we enjoy the lengthening of days as we move from the budding spring of Nisan toward the summer solstice some weeks from now, we can carry with us the ancient wish of the rabbis: that we spend less time inventing paperwork for ourselves and more time appreciating and learning from the natural world of God's creation.