Does the hand become impure by touching a dry urine stain on trousers, and do the things that the hand subsequently touches also become impure, and what should one do who is in doubt about this?

If urine soils a garment and then dries, and a dry hand touches it, neither the hand nor anything it subsequently touches becomes impure. This is because if an impure object meets a pure object while both are dry, it does not render the latter impure. However, if the hand is wet and touches the impure spot, the matter is a subject of scholarly disagreement. A Muslim should turn away from doubts and whisperings (waswas) in this regard and hasten to wash the impure spot.