How can one differentiate between questions stemming from intrusive thoughts (waswasah) and natural questions?

One must learn the rulings of Islamic law and ask the people of knowledge about what they do not know. As for the whispers (waswas) that arise after knowing the Sharia ruling, they must be ignored and not given any attention. For example, if someone performs ablution (wudu) and then has whispers that they did not wash a limb, they should not pay attention to that doubt. If the Mufti (issuer of fatwas) alerts the questioner that their question stems from waswas, then they must avoid asking about it and similar matters, and completely ignore the whispers.