Mukhtasar Muslim (Abridged) 741 — Standing and tying the camel before

It is narrated from Ziyad bin Jubair that Ibn Umar (may Allah be pleased with them both) saw a man making a camel sit down and slaughtering it. He said, "Make it stand up, tie its leg, and then slaughter it. This is the Sunnah of your Prophet Muhammad (peace and blessings be upon him)."