 the doctor was accused of having given him the drink in order to kill him because of the virtue of sulayman ibn musa and his position in islam. the doctor was a christian so hisham ordered him to drink from where he had given him the drink suspecting that he had been given poison or something similar and that was the case.
وكان الطبيب قد اتهم أن يكون إنما سقاه ليقتله لفضل سليمان بن موسى ومكانه من الاسلام، وكان الطبيب نصرانيا، فلذلك أمره هشام أن يشرب من حيث سقاه تهمة له أن يكون إنما سقي سما وما أشبهه فكان ذلك كذلك.