Narrated Jundab bin 'Abdullah: that the Messenger of Allah (ﷺ) said: "Whoever says (something) about the Qur'an according to his own opinion and he is correct, yet he has committed a mistake."
And there are other versions of the same Hadith in "Chapters on Tafsir - Jami` at-Tirmidhi" (the first three ones in that chapter).
What is the Hadith talking about when it says "Whoever says (something) about the Qur'an..."? Is it talking about formulating our own Tafseer of the Qur'an?
If yes, then does it mean we must follow the Tafseer given out by Prophet Muhammad (SAW) only or can we follow the Tafseer of other scholars too?
If only of Prophet Muhammad (SAW) and if I'm not wrong that Prophet Muhammad (SAW) hasn't explained about every verse of Qur'an, then doesn't it become difficult to understand the Qur'an?
If yes, to Q1 (above), then how is it possible that Qur'an while being clear and apparent most of the time still has to be relied on Tafseer? And only of Prophet Muhammad (SAW) (if Yes to Q2 above)?