Good Manners and Form (Al-Adab)
Ṣaḥīḥ al-Bukhārī 5977
أَلاَ أُنَبِّئُكُمْ بِأَكْبَرِ الْكَبَائِرِ ـ قَالَ ـ قَوْلُ الزُّورِ ـ أَوْ قَالَ ـ شَهَادَةُ الزُّورِ
alā unabbiʾukum biʾakbari al-kabāʾiri qāla qawlu az-zūri aw qāla shahādah az-zūri
Transliteration generated from the Arabic vowel marks
The full narration
Narrated Anas bin Malik:Allah's Messenger (ﷺ) mentioned the greatest sins or he was asked about the greatest sins. He said, "To join partners in worship with Allah; to kill a soul which Allah has forbidden to kill; and to be undutiful or unkind to one's parents." The Prophet (ﷺ) added, "Shall I inform you of the biggest of the great sins? That is the forged statement or the false witness." Shu`ba (the sub-narrator) states that most probably the Prophet said, "the false witness
Source
Ṣaḥīḥ al-Bukhārī · 5977