Is there a sacred shape or holy symbol in Islam?

No. There is no sacred shape in Islam. What is holy is the right understanding of the one God, and He has no form, not even as a symbol.

In some religions there are sacred shapes and signs that are venerated and believed to hold a special power. There is nothing like this in Islam. The core of the faith is the oneness of God. Whoever truly believes in the one God cannot give Him a form, not even as a symbol. The verses above say that nothing resembles Him and that no sight can reach Him.

How then does God make Himself known? A comparison with the sun helps. Those who have eyes see the world in the light of day. Those who cannot see still feel its warmth. And everyone experiences what it does. In the morning life awakens, and people get up and go to their work. The sun convinces through what it does.

It is the same with God, only much deeper. His attributes are not material. They are eternal qualities such as mercy, knowledge and justice. Whoever carries this image of God in the heart will be guided to the right path. There is no need for a symbol or shape to focus on.

Even the places Muslims honour, such as the Ka‘bah, are not objects with power of their own. They are honoured because God has made them signs of devotion. The hadith above shows this very clearly. A stone remains a stone. It is honoured only out of obedience, not because it could bring benefit or harm.