Is it obligatory to rule the foot and the places it trod as impure if something was touched and believed to be impure, then this belief ceased, and its reason became unknown?

The default state of anything that touches you is purity, and it is not ruled as impure except with certainty. So, if something wet touches you, and you do not know what it is, you are not obligated to smell it to identify it. Your belief that what touched you is impure is a mistaken belief and not based on a sound foundation. Rather, it is ruled as pure, as is everything your foot touched thereafter. We warn you against indulging in obsessive thoughts.