Ruling on one who doubts his ritual purity merely from touching

The question: This is a letter, O Shaykh, very long and the handwriting is weak, but we were able to summarize it as follows.
The Shaykh: Leave it...
The presenter: Yes.
The Shaykh: Leave it for another session so we can reflect on it...
The presenter: No, I have summarized the content of the letter now. It says: If a person is in a state of ritual purity and he doubts that he has become ritually impure merely by touching a person who is ritually impure, or by sitting with a group whose purity he does not know, which makes me repeat the ghusl or the wudu. Abdul Aziz Salman Muhammad al-Rashid from Tayma?
Answer: These are obsessions with no basis. If his original state is purity, there is no basis for impurity. If his original state is purity and then he doubts whether he has broken his purity by passing wind or something else, the original state is purity and he should not pay attention to this. Or if his body is pure and his clothes are pure, and then he doubts whether someone has affected his clothes with impurity, the original state is purity and he should not pay attention to this. This is from the obsessions of Satan and from illusions that have no basis. Likewise, if he sits with people whose purity he doubts, that does not harm him, and the original state is purity in him and in them. So he should not be obsessed with or imagine these false things. The original state is purity in his clothes and his body, and purity from the state of ritual impurity. This purity is not removed except by certainty that he has broken his purity, in which case he performs wudu, or by certainty that a known impurity has affected his clothes, in which case he purifies what was affected. As for these illusions, they have no basis.