In Jummah, when the imaam begins the khutbah, the people sit with their arms folded (right hand over the left wrist) just like in salah. When the imaam sits and stands up to give the second part of the khutbah, people put their hands on their knees (just like in tashahhud) Is there any bases for this or an innovation? And lastly how should one sit during a khutbah?