If the dome outside the mosque appears as if it is facing downwards in a symbol of the believer's humility before his Lord, then from the inside it gives the opposite impression, expressing an upward and upward vertical movement, so that the believer, while practically living the atmosphere of worship inside the mosque, is surrounded by the suggestion of elevation, sublimity, and transcendence.
The dome in the mosque is more than an architectural phenomenon used for many purposes. It is a symbol of the dome of the highest heaven towards which eyes long and hearts move towards it, in a mixture of hope, fear, love and reverence.
Domes appeared in buildings in general, first in Asia, then they moved to the Persians, Greece, and then the Romans before the Muslims received them. No style of the major human arts is devoid of domes except the ancient Egyptian style. Then domes continued to appear in mosques until it is rare to see a mosque with a minaret without a dome.