Kadosh, Kadosh, Kadosh • MBD / Ein Od Milvado

In Hilchos Kedusha (Orech Chaim, 125:3), the Alter Rebbe quotes this entire passage as a "smach" for the custom to lift our feet during the words "Kadosh", "Boruch" and "Yimloch". So, of course, it took us eight times longer than usual to get through the se'if.