Ubaidullah b. Abu Bakr said: I heard Anas b. Malik saying: The Messenger of Allah (ﷺ) talked about the major sins, or he was asked about the major sins. Upon this he observed: Associating anyone with Allah, killing of a person, disobedience to parents. He (the Prophet (ﷺ) further) said: Should I not inform you about the gravest of the major sins, and (in this connection) observed: False utterance or false testimony. Shu'ba said. It was most probably" false testimony".
Source: sunnah.com
Other translations
Arabic
وَحَدَّثَنَا مُحَمَّدُ بْنُ الْوَلِيدِ بْنِ عَبْدِ الْحَمِيدِ، حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، حَدَّثَنَا شُعْبَةُ، قَالَ حَدَّثَنِي عُبَيْدُ اللَّهِ بْنُ أَبِي بَكْرٍ، قَالَ سَمِعْتُ أَنَسَ بْنَ مَالِكٍ، قَالَ ذَكَرَ رَسُولُ اللَّهِ صلى الله عليه وسلم الْكَبَائِرَ - أَوْ سُئِلَ عَنِ الْكَبَائِرِ - فَقَالَ " الشِّرْكُ بِاللَّهِ وَقَتْلُ النَّفْسِ وَعُقُوقُ الْوَالِدَيْنِ " . وَقَالَ " أَلاَ أُنَبِّئُكُمْ بِأَكْبَرِ الْكَبَائِرِ " . قَالَ " قَوْلُ الزُّورِ " . أَوْ قَالَ " شَهَادَةُ الزُّورِ " . قَالَ شُعْبَةُ وَأَكْبَرُ ظَنِّي أَنَّهُ شَهَادَةُ الزُّورِ .
sunnah.com