قالوا تَاللَّهِ إِنَّكَ لَفي ضَلالِكَ القَديمِ

They said: ‘By God, you persist in your inveterate error.’

EXEGESIS

Qadīm (inveterate) means something that has been established priorly. Here it implies that his perceived error was something that had persisted for a long time.

EXPOSITION

They said: ‘By God, you persist in your inveterate error’: this was again an example of how they mistreated their father, similar to what they said in the beginning of the story, Our father is indeed in manifest error (verse 8). Based on this we can also say that error is used in the same sense in both verses to mean that he was persisting in his unfair love for Prophet Joseph (a).[1] It has also been said that this referred to his assumption that Prophet Joseph (a) was still alive,[2] however considering verse 8, the former interpretation is more plausible, although there is no problem assuming both are meant.

In any case, error (ḍalāl) should not be understood to mean being misguided in religion, which would entail them being disbelievers.

[1] Mizan, 11/244-245.
[2] Tibyan, 6/193; Zamakhshari, 2/504; Tantawi, 12/265. The former two entertain both options.