Cause and Effect...

Those who throw dust at the sun, the dust falls in their own eyes.

Bowl of Saki, by Hazrat Inayat Khan
Commentary by Pir-o-Murshid Inayat Khan:

Raise not dust from the ground; it will enter into your eyes. Sprinkle some water on it that it may settle down and lie under your feet.

To delve into a matter which matters little, is like raising dust from the ground.

Man forms his future by his actions. His every good or bad action spreads its vibrations and becomes known throughout the universe.

The more spiritual a man is, the stronger and clearer are the vibrations of his actions, which spread over the world and weave his future. The universe is like a dome: it vibrates to that which you say in it, and echoes the same back to you. So also is the law of action: we reap what we sow.