How can the Prophet’s — may Allah bless him and grant him peace — saying: "Indeed, Allah has pardoned for my Ummah what they speak to themselves, as long as they do not act upon it or speak of it," be reconciled with the scholars' assertion of the obligation to consult people of knowledge to remove dangerous doubts in religion? And is this considered an utterance of what is within oneself, thereby exiting the scope of divine pardon?

There is no contradiction between the Hadith (definition): "Indeed, Allah has pardoned for my nation what they whisper to themselves, as long as they do not act upon it or speak of it," and the obligation to consult scholars regarding dangerous doubts. The Hadith refers to waswasah (whispers/obsessive thoughts) that do not settle in the soul, whereas serious doubt that contradicts the heart's conviction is an invalidator of faith, and a Muslim must consult scholars to remove it.