Hazrat Samurah bin Jundub (may Allah be pleased with him) once said during a sermon that the Messenger of Allah (peace and blessings be upon him) said: "Do not let Bilal's call to prayer or this whiteness deceive you until the true dawn appears."
Hadith Referenceمسند احمد / أول مسند البصريين / 20149
Hadith Gradingحکم دارالسلام:صحيح لغيره، م: 1094، وهذا إسناد حسن