It is narrated from Sayyidah Aishah Siddiqah (may Allah be pleased with her) that the Prophet (peace and blessings be upon him) said: "Islam is cleanliness, so adopt cleanliness, for none but a clean person will enter Paradise."
Imam al-Tabarani recorded it in al-Mu'jam al-Awsat. Its chain contains a narrator, Nu'aym bin Muwarri', and he is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب اللباس / 8579