كَجَمْعِ الضِّدَّيْنِ
Such as joining two contradictory states.
A single body cannot, in the same time, location, and relevant respect, be both wholly at rest and in motion. If the time or respect changes, the conditions may no longer conflict, but that is a different proposition.
Intrinsic impossibility does not refer to a mere shortage of strength. The issue is whether the demanded state describes a coherent possibility at all. Charging a person to realize a contradiction is not an ordinary instance of religious obligation.