The Prophet saw some sputum in the prayer direction of the mosque and he became so angry that his face turned red. Then a woman from among the Ansar came and scraped it off, and put some Khaluq on that spot. The Messenger of Allah said: "How good this is."
Sunan Ibn Majah Book 4, Hadith 28
← Previous Hadith The Messenger of Allah saw some sputum on the wall of the mosque. He picked up a stone and scraped it off, then he said, "If anyone of you needs to spit, he should not spit in fro not of him or to his right; let him spit to his right; let him spit to his left or under his left foot."

Sunan Ibn Majah Book 4, Hadith 27 Next Hadith → "The Messenger of Allah saw some sputum in the prayer direction of the mosque, when he was praying in front of the people. He scratched it off, then when the prayer was over, he said: 'When anyone of you is performing prayer, Allah is before him, so none of you should spit toward the front while praying.'"

Sunan Ibn Majah Book 4, Hadith 29