@Godobeyer
According to these Traditions, not everyoner is well-grounded in knowledge of interpretation. Only Prophet Muhammad, and Imam Ali, and His sons:
Muhammad ibn abu ‘Abdallah and Muhammad ibn al-Hassan have narrated from Sahl ibn
Ziyad and Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad, both of them
from al-Hassan ibn al-‘Abbas ibn al-Harish from abu Ja‘far al-Thani (a.s.) who has said the
following. "Abu ‘Abdallah (a.s.) has said.....
If they would ask, "Who are the ones well-grounded in knowledge?" Say, "They are those in
whose knowledge there is no disharmony." If they would ask, "Who is he?" Say, "the Messenger of Allah was such a person. Did he convey such knowledge to the first one (Khalifa)?" If they say, "Yes, the Messenger of Allah did convey." Ask, "Did the Messenger of Allah die and the Khalifa after him had the knowledge free of disharmony ?" If they would say, "No, there was no such Khalifa with the knowledge free of disharmony." Say, "(This is not logical.) The successor of the Messenger of Allah is supported (has the Divine support) and the Messenger of Allah does not appoint a Khalifa who would not judge by the laws of Allah. The Messenger of Allah will not appoint a Khalifa except one who is just like him, excluding prophet-hood. If the Messenger of Allah did not appoint a Khalifa in his knowledge
anyone, he ( Allah forbid) caused to go astray the people of coming generations."
Source: Bihara al anwar Volume 51-53, part 2.
It is narrated from him from Muhammad ibn Ali from ibn Mahbub from ‘Abd al-‘Aziz al-‘Abdi from abu ‘Abdallah (a.s.) who has said the following about the words of Allah, the Most Holy, the Most High. "
In fact, the Quran consists of illustrious verses that exist in the hearts of those who have knowledge. . . ." (29:49) ‘They are the Imams (a.s.)’.
A number of our people has narrated from Ahmad ibn Muhammad from al-Husayn ibn Sa‘idfrom an-Nadr ibn Suwayd from Ayyub ibn Hurr and ‘Imran ibn Ali from abu Basir from abu ‘Abdallah (a.s.) who has said the following. "
We are the people well-grounded in knowledge and we are the ones who know how to interpret it."
Ali ibn Muhammad has narrated from ‘Abdallah ibn Ali from Ibrahim ibn Ishaq from‘ Adallah ibn Hammad from Burayd ibn Mu‘awiya who has narrated the following from either one of the Imams (a.s.) about the words of Allah, Allah, the Most Majestic, the Most gracious. "No one knows its true interpretations except God and those who have a firm grounding in knowledge . . ." (3:7).
The Holy Prophet is the best among the people well-grounded in knowledge. Allah, the Most Majestic, the Most gracious, taught him all that He had revealed to him in the form of original text and in the form of interpretations. Allah, the Most Majestic, the Most gracious, would not reveal anything to him that he would not know the meaning thereof. The successors of the Holy Prophet (s.a.) after him knew all revelations.
As for those who do not know the interpretations thereof, when the scholar speaks to them with knowledge, they say, "We believe in it, for all of this is from our Lord." The Holy Quran consists of specific, general, clear, not so clear, abrogating and abrogated statements. The people who are well-grounded in knowledge know all of the Holy Quran."
Al-Husayn ibn Muhammad has narrated from MuAlia ibn Muhammad from Muhammad ibn’Uwarma from Ali ibn Hassan from ‘Abd al-Rahman ibn Kathir from abu ‘bdallah (a.s.) who has said the following. "
People well-grounded in Knowledge stands for Amir al-Mu’minin Ali (a.s.) and the Imams after him."
Source: Al-Kafi, volume 1
So, whatever interpretations the Well-grounded in knowledge gave, that is the correct view, according to Traditions, and Quran verse 3:7.