a beam of (something)
a beam of (something)
informal A small but steadfast amount or source of something hopeful or positive. My lovely daughter has been a beam of joy in such a trying year of hardship. The charity is the sole beam of comfort to the many people displaced by war who have been reduced to such squalid conditions.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.