Examine Mana

For the duration, you sense the presence of magic within 60 feet of you. If you sense magic in this way, you can use your action to see a faint aura around any visible creature or object in the area that bears magic, and you learn its school of magic, if any.

The spell can penetrate most barriers, but it is blocked by 3 foot of stone, 3 inch of common metal, a 1 inch thick sheet of lead, or 9 feet of wood or dirt.

In addition, this spell allows you to "Study" a magical source, generally a creature with the Spellcasting ability. Studying a magical source gives you resistance to any magical damage cast from this source, and advantage on counter spell rolls against the source.