in Thoreau’s Journal:

A sharp cutting air— This is a pretty good winter morning however— Not one of the rarer. There are from time to time mornings—both in summer & winter when especially the world seems to begin anew—beyond which memory need not go—for not behind them is yesterday and our past life—when as in the morning of a hoar frost there are visible the effects of a certain creative energy—the world has visibly been recreated in the night—mornings of creation I call them.