Sunan at-Tirmithiy كتاب البر والصلة باب ما جاء فى الصدق والكذب
No characteristic was more detestable to the Messenger of God, peace and blessings of God be upon him, than lying. Whenever a man told a lie in the presence of the Prophet, peace and blessings of God be upon him, he would remain troubled until he knows that the man has repented from it. Click on ḥadīth to read more