“…A window you shall make for the ark.” (Genesis 6:16)
The Hebrew word for window is ‘tzohar’, which can also mean illumination or light. The word for ark is ‘teivah’, which can also mean word.
Based on this, the Baal Shem Tov derives a teaching about prayer:
You shall illuminate your words! Polish them with your inner passion and sincerity so that they shine!