Surah Yusuf 12:18

وَجَآءُو عَلَىٰ قَمِيصِهِۦ بِدَمٍ كَذِبٍ ۚ قَالَ بَلْ سَوَّلَتْ لَكُمْ أَنفُسُكُمْ أَمْرًا ۖ فَصَبْرٌ جَمِيلٌ ۖ وَٱللَّهُ ٱلْمُسْتَعَانُ عَلَىٰ مَا تَصِفُونَ

And they brought upon his shirt false blood. [Jacob] said, "Rather, your souls have enticed you to something, so patience is most fitting. And Allāh is the one sought for help against that which you describe."

Translation: Saheeh International

Tafsir

And they came with false blood on his shirt ‘alā qamīsihi has the status of an accusative of the verb because it is an adverbial qualifier meaning fawqa qamīsihi they slaughtered a lamb and dabbed it his shirt with its blood — but they forgot to tear it the shirt — and they said that it was his blood. …

Excerpt from Tafsir al-Jalalayn, commentary on 12:18, via Quran.com. The reader has the full commentary and 9 more tafsirs.