Tafsir of An-Nisa' 4:106

(And seek forgiveness of Allah) for what you said to Qatada, or for what you contemplated regarding the affair of Tu'mah. As for his innocence—based on the apparent state of affairs and what he (may Allah's peace and blessings be upon him) said to Qatada—contemplating a matter, especially when one believes it to be the truth, is not a sin for which one must seek forgiveness. However, due to the greatness of the Prophet (may Allah's peace and blessings be upon him), Allah Almighty’s protection of him, and His keeping him far removed from anything that might suggest a deficiency—far be it from him—He commanded him to seek forgiveness to increase his reward and to guide him toward verification. Indeed, that which is not a sin, and which might even be considered a good deed from someone else, if it emanates from him (peace and blessings be upon him), given his greatness and his praiseworthy station, approaches the status of a sin. Therefore, there is no justification in the command to seek forgiveness for denying his infallibility, as some have claimed. It has also been said that the meaning is: "And seek forgiveness for those who acquitted that traitor."

(Indeed, Allah is ever Forgiving, Merciful)

An exaggeration in forgiveness and mercy for those for whom He seeks forgiveness.