Surah Al-Kahf — Ayah 5 (18:5)

English translation (Saheeh International)

They have no knowledge of it,¹ nor had their fathers. Grave is the word that comes out of their mouths; they speak not except a lie.

1. - i.e., they could not have had knowledge of something which is not true.

Brief commentary

These fabricators have no knowledge of their claim that Allah has a son and nor did their fathers whom they followed in this regard have any knowledge. This statement which has escaped their mouths without any understanding is heinous. They only speak a lie which has no basis or support.