Hadith on Major Sins: The worst sins are polytheism, disobedience to parents, killing a person without right of justice, and giving false testimony

Anas reported: The Prophet, peace be upon him, said concerning major sins, “They are associating partners with Allah, disobedience to parents, killing a person, and speaking falsehood.”
[Sahih Muslim, Book 1, Number 159]

عَنْ أَنَسٍ  عَنْ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فِي الْكَبَائِرِ قَالَ الشِّرْكُ بِاللَّهِ وَعُقُوقُ الْوَالِدَيْنِ وَقَتْلُ النَّفْسِ وَقَوْلُ الزُّورِ

صحيح مسلم كتاب الإيمان باب بيان الكبائر وأكبرها