موطا امام مالك رواية ابن القاسم
Muwatta Imam Malik (Riwayat Ibn al-Qasim)
Discussion on Forbidden and Unlawful Matters
Spitting towards the qiblah is forbidden
Hadith 592
460- وبه: أن رسول الله صلى الله عليه وسلم رأى فى جدار القبلة بصاقا أو مخاطا أو نخامة فحكه.
And with the same chain of narration (from Sayyidah Aisha, may Allah be pleased with her), it is narrated that the Messenger of Allah, peace and blessings be upon him, saw spit or phlegm on the wall facing the qiblah, so he scraped it off (and cleaned it).
