The Prophet (peace and blessings be upon him) said:
"Shall I not tell you about the greatest of sins (the major sins)? Associating partners with Allah, disobedience to parents, and speaking falsehood."
Hadith Referenceصحیح الجامع الصغیر / حرف الألف / 2628
Hadith Gradingالألبانی:صحيح
Hadith Takhrij[حم ق ت] عن أبي بكرة. مختصر مسلم ٤٦.