«وَبَرِئَ بَرَاءَةَ الذِّئْبِ مِنْ دَمِ ابْنِ يَعْقُوبَ»
And the youth was cleared, like the wolf cleared of the blood of Jacob’s son.
This alludes to the Qurʾānic account of Joseph: his brothers blamed a wolf, although their story was false. Barāʾat al-dhiʾb min dam ibn Yaʿqūb became an idiom for innocence. In this tale the youth’s release is described in that idiom, but the reader must remember that no ordinary evidentiary investigation established the original accusation.