Kommentar zu Tahorot 3:6

בחזקת טהרה – for even though that regarding doubtful ritual impurity in the private domain is considered as doubtfully impure and this alleyway is the private domain, nevertheless since the doubt is in a matter where it the temperament/disposition [of the participants] is lacking to be able to be asked, as for example, a deaf-mute, imbecile and/or a minor child, he is considered pure in his status of doubt, for this we derive from Scriptural verses, as it is written (Leviticus 7:19): “Flesh that touches anything impure shall not be eaten.” This implies that something that is definitely impure shall not be eaten; if it is doubtfully impure it may be eaten, as it is written (Leviticus 7:19): “Only he who is pure may eat such flesh.” Someone who is definitely pure may eat it, but if he is doubtfully impure/doubtfully pure, he shall not eat it. But is it not that we learn from it here that when he has awareness/understanding to be interrogated, [as opposed to] when he doesn’t have awareness/understanding to be interrogated.

If a deaf-mute, a person not of sound senses, or a minor was found in an alley way that contained something that was unclean, he is presumed to be clean. An alleyway is considered to be a private domain. In this alleyway there is something that is impure, but we are not sure if the person came into contact with it. The rule in section three will state that if someone or something cannot be asked if they came into contact with something impure, they are ruled to be pure. A deaf-mute, and a person not of sound senses and a minor are all considered to lack what we might call awareness or intelligence. One cannot legally ask them if they came into contact with the impure thing. Therefore, they are pure.

וכל הפקח – that he has awareness/understanding to be interrogated. If he does not know if he walked in a place of defilement or not, he is under the presumption of defilement. For someone of doubtful defilement in the private domain, his [presumption of] doubt is impure which we derive from [the case of] the Sotah/woman suspected by her husband of being unfaithful, and there is a doubt if she is defiled or not and this doubt is in a place of a married woman’s hiding with a man under suspicious circumstances, that is, in the private domain, and the All-Merciful stated (Numbers 5:13): “and she keeps secret the fat that she has defiled herself without being forced,” but a woman suspected by her husband of being unfaithful has awareness/understanding to be interrogated if she has been defiled or not.

But any one of sound senses is presumed to be unclean. The person of sound senses can be asked, but in this case he doesn't know if he had contact with the impure thing. Therefore, he is impure.

And anyone/anything that lacks understanding to be inquired of is in a case of doubtful uncleanness presumed to be clean. This is the general rule that explains section one.