Some researchers relate the Arabic letters to constellations. Some letters have the nature of the fiery triplicity. That is, Fire Nature: Hot and Dry. Others have the nature of the dusty (earthy) triplicity (Dust nature: Cold and Dry). A third group of letters has the nature of airy triplicity (Air nature: Hot and Moist). A fourth group has the nature of watery triplicity (Water nature: Cold and Moist)

fiery nature		�������� ������� ��� ���� ��� �����
dusty nature		�������� �������� ���� ���� ��� ������
airy nature		�������� �������� ��� ��� ��� ������
watery nature		�������� ������� ���� ��� ��� �����

Source: Lesan Al-Arab (The Arab Tongue) by Ebn Manzour - Dar El-Maaref; Cairo