Sahih Muslim Book 32, Hadith Number 6335.

Chapter : He who goes in the mosque or in the bazaar or a place of gathering like it with a weapon should see that the spearhead does not harm anyone.

Abu Musa reported Allah’s Apostle (may peace be upon him) assaying: He who amongst you moves in the mosque or in the bazar and there is an arrow with him he should take hold of its iron-head in his palm, so that none amongst the Muslims should receive any injury from it, or he said, should catch its iron-head.