The Prophet said, If while you are praying, somebody intends to pass ...

Hadith 4:495

Narrated Abu Said Al-Khudri:

The Prophet said, "If while you are praying, somebody intends to pass in front of you, prevent him; and should he insist, prevent him again; and if he insists again, fight with him (i.e. prevent him violently e.g. pushing him violently), because such a person is (like) a devil."

in charge of the Zakat of Ramadan (i.e. Zakat-ul-Fitr). Someone came to me and started scooping some of the foodstuff of (Zakat) with both hands. I caught him and told him that I would take him to Allah's Apostle." Then Abu Huraira told the whole narration and added "He (i.e. the thief) said, 'Whenever you go to your bed, recite the Verse of "Al-Kursi" (2.255) for then a guardian from Allah will be guarding you, and Satan will not approach you till dawn.' " On that the Prophet said, "He told you the truth, though he is a liar, and he (the thief) himself was the Satan."