﴿ فَلَمَّا جَهَّزَهُم بِجَهَازِهِمْ جَعَلَ ٱلسِّقَايَةَ فِى رَحْلِ أَخِيهِ ثُمَّ أَذَّنَ مُؤَذِّنٌ أَيَّتُهَا ٱلْعِيرُ إِنَّكُمْ لَسَٰرِقُونَ ﴾

“And [later,] when he had provided them with their provisions, he placed the [King's] drinking-cup in his brother's camel-pack. And [as they were leaving the city,] a herald called out: "O you people of the caravan! Verily, you are thieves!”

Please check ayah 12:72 for complete tafsir.