Abdullah bin al-Samit (may Allah have mercy on him) narrates from Sayyiduna Mu'adh bin Jabal (may Allah be pleased with him) that he was ill and spat to his right - or intended to spit to his right - and then said: "I have never spat to my right since I accepted Islam."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17477