Mukhtasar Muslim

It is narrated from Sayyiduna Abu Hurairah, may Allah be pleased with him, that the Messenger of Allah, peace and blessings be upon him, saw spit in the mosque facing the qiblah, so he turned towards the people and said: "What is the matter with you that one of you stands facing his Lord, then spits in front of himself? Does any one of you like that someone should face him and then spit in front of him? When any one of you feels the urge to spit, he should spit to his left under his foot, and if there is no place, then he should do like this (the Prophet, peace and blessings be upon him, demonstrated this action)." Qasim (who is the narrator of this hadith) stated that he spat in his garment and then rubbed that part of the garment together.