The Prophet ﷺ said, "When one of you stands to pray, he must not spit in front of him, for he is in private conversation with Allah as long as he is at his place of prayer. Nor should he spit to his right, for there is an angel on his right. Let him spit to his left or beneath his foot and bury it."
عن النبي ﷺ قال: إذا قام أحدكم إلى الصلاة فلا يبصقن أمامه، فإنما يناجي الله مادام في مصلاه، ولا عن يمينه، فإن عن يمينه ملكا، وليبصقن عن يساره أو تحت قدمه فيدفنها.
Bukhari narrated it in "The Prayer" (416) from Ishaq bin Nasr, who said, Abdul-Razzaq told us, from Mamar, from Hammam, who heard Abu Hurairah, and he related the hadith. Muslim also narrated it (547) through another route from Abu Hurairah, but it does not mention the angels.