Sayyiduna Abu Hurairah (may Allah be pleased with him) and Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) narrate: The Prophet (peace and blessings of Allah be upon him) saw phlegm stuck (on the wall) in the direction of the Qiblah, so he took a pebble and scraped it off with it. Then he said: No one should ever spit in the direction of the Qiblah, nor to his right side. He should spit to his left side or under his left foot.
Hadith Referenceصحیح ابن حبان / كتاب الصلاة / 2268
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح - «الصحيحة» (1274)، «الإرواء» (184): ق.فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده صحيح على شرط مسلم، وحرملة قد توبع، حميد بن عبد الرحمن: هو ابن عوف الزهري المدني.