The phrase "cut off" (الأَبْتَرُ - *al-abtar*) in Surah Al-Kawthar, Ayah 3, refers to being cut off from progeny, remembrance, and all goodness, particularly divine favor.

Linguistically, *al-abtar* derives from *batara*, meaning to cut off or sever. It specifically denotes an animal with its tail cut off, metaphorically applied to a man without male offspring, implying an end to his lineage and legacy.

According to Ibn Kathir, the verse was revealed in response to disbelievers like Abu Lahab, Al-`As bin Wa'il, `Uqbah bin Abi Mu`ayt, or Ka`b bin Al-Ashraf, who mocked the Prophet Muhammad (ﷺ) after the death of his sons, claiming he was "cut off" (Source 1, 3, 4). They believed that without male descendants, his remembrance and influence would cease.

However, the Quran refutes this, declaring that it is the Prophet's enemies who will be truly *abtar* – cut off from goodness, divine mercy, and lasting remembrance, while Allah preserved the Prophet's legacy for all time (Source 1, 3). This contrasts with the abundant goodness (Al-Kawthar) granted to the Prophet (Source 6). The verse implies being cut off from worldly and, more importantly, eternal blessings.

📚 Sources: Classical tafsir (multi-source)