A sharp sword cuts deepest.
Swords have traditionally, in the Tarot, been associated with thoughts. The sharper the sword, the sharper the mind and so forth. The trouble with a razor sharp mind is the collateral damage these thoughts can inflict when given voice. Continue to whone your mind but hold back on expressing your views. This symbol is a warning and a gentle suggestion all at once. Have you been speaking your truth to those who yet to start the great work which is upon ourselves? Are you mouthing off in front others who are farther along the path than yourself? The dangers are obvious in both cases. So heed the warning suggestion. Watch, listen, teach and learn by actions rather than words. This is difficult. A sharp mind and the joy of word play can be both addictive and quickly get out of hand. Even when the intent is pure, the way words are received is not always as they are sent.