Sunan at-Tirmithiy كتاب البيوع باب ما جاء فى التغليظ فى الكذب والزور ونحوه
On the subject of grave sins, the Prophet, peace and blessings of God be upon him, mentioned, “Associating [anything in worship] with God, being undutiful to [one’s] parents, killing a soul (1), and uttering falsehood.” Footnotes: (1) i.e., killing a person, without legitimate right to do so. Click on ḥadīth to read more