Purity is half of faith

On the authority of Abu Malik al-Harith ibn Asim al-Ash'ari (may Allah be pleased with him), that the Messenger of Allah (may Allah bless him and grant him peace) said: "Purity is half of faith. “Praise be to Allah” fills the scales. “Glory be to Allah and praise be to Allah” fill — or fills — what is between the heavens and the earth. Prayer is light, charity is a proof, patience is radiance, and the Quran is an argument for you or against you. Every man goes out and trades with his own soul, either setting it free or bringing it to ruin."

Related by Muslim.

[Muslim 223]