You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Quran

Context:
According to Shia beliefs, those who are firmly rooted in knowledge like Muhammad and the imams know the secrets of the Quran. According to Tabatabaei, the statement "none knows its interpretation except God" remains valid, without any opposing or qualifying clause. Therefore, so far as this verse is concerned, the knowledge of the Quran's interpretation is reserved for God. But Tabatabaei uses other verses and concludes that those who are purified by God know the interpretation of the Quran to a certain extent.

Question:
How must God have treated those who are qualified to know Quranic sectets?

purified