What is the reconciliation between the saying of the Messenger of Allah, peace and blessings be upon him, "If He wills, He punishes him, and if He wills, He pardons him," and the saying of Allah the Almighty, "Say, 'O My servants who have transgressed against themselves [by sinning], do not despair of the mercy of Allah. Indeed, Allah forgives all sins' " and the hadiths that support this?

There is no contradiction between the texts of revelation, for all of it is from Allah, and if a contradiction appears, it is due to differing understandings. The absolute texts regarding the forgiveness of sins are qualified by repentance, as Ibn Kathir mentioned when interpreting the verse from Surah Az-Zumar (Indeed, Allah forgives all sins), stating that it is an call for sinners to repent and return to Allah. Furthermore, these texts are qualified by Allah's will, for Allah forgives whom He wills, and that is the repentant one, and the proof for this is His saying, the Most High: (And return [in repentance] to your Lord) and His saying: (But indeed, I am the Forgiver of whoever repents).