Sayyiduna Abu Umamah (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings be upon him) called for his leather socks (khuffs) in order to put them on. He (peace and blessings be upon him) put on one of them, then a crow came and carried off the other, then dropped it, and a snake came out of it. Thereupon the Messenger of Allah (peace and blessings be upon him) said: "Whoever believes in Allah and the Last Day should shake out his leather socks before putting them on."
Hadith Referenceالمعجم الكبير للطبراني / باب الصاد / 7589