AKA sunbeams, aka crepuscular rays. If you ever see crepuscular rays when you look at the sunset, turn around and face the opposite direction. You may see dark counterparts, known as anticrepuscular rays. They're the shadows of the clouds causing the sunbeams in the west. Anticrepuscular rays converge on the eastern horizon, opposite the sun's position in the west.

https://apod.nasa.gov/apod/ap200318.html

https://apod.nasa.gov/apod/ap160627.html

The same holds at sunrise, of course.