'A'isha reported: we (intended to pour) medicine in the mouth of Allah's Messenger (ﷺ) in his illness, but he pointed out (with the gesture of his hand) that it should not be poured into the mouth against his will. We said: (It was perhaps due to the natural) aversion of the patient against medicine. When he recovered, he said: Medicine should be poured into the mouth of every one of you except Ibn 'Abbas, for he was not present amongst you.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنِي مُحَمَّدُ بْنُ حَاتِمٍ، حَدَّثَنَا يَحْيَى بْنُ سَعِيدٍ، عَنْ سُفْيَانَ، حَدَّثَنِي مُوسَى بْنُ أَبِي، عَائِشَةَ عَنْ عُبَيْدِ اللَّهِ بْنِ عَبْدِ اللَّهِ، عَنْ عَائِشَةَ، قَالَتْ لَدَدْنَا رَسُولَ اللَّهِ صلى الله عليه وسلم فِي مَرَضِهِ فَأَشَارَ أَنْ لاَ تَلُدُّونِي . فَقُلْنَا كَرَاهِيَةُ الْمَرِيضِ لِلدَّوَاءِ . فَلَمَّا أَفَاقَ قَالَ " لاَ يَبْقَى أَحَدٌ مِنْكُمْ إِلاَّ لُدَّ غَيْرُ الْعَبَّاسِ فَإِنَّهُ لَمْ يَشْهَدْكُمْ " .
sunnah.com