Hazrat Ikrimah says that when revelation came to the Prophet صلی اللہ علیہ وسلم , the Quraysh said that Muhammad has been cut off from us. So the verse {إنَّ شَانِئَک ہُوَ الأَبْتَرُ } was revealed, that the one who said this to you, he is the one who is cut off from progeny.