דברי הימים ב, פרק ל״ג, פסוק י״ח

The final summary of King Manasseh's reign directs attention to the historical records that document the remainder of his actions, his turn toward God, and the rebukes he received. The seers who delivered these warnings were the prophets of the time. They spoke directly to the king and carefully wrote down the details of his sins [מלבי״ם, ביאור שטיינזלץ]. All of these events are thoroughly described in the historical chronicles of the kings of Israel [מצודת דוד, ביאור שטיינזלץ].

During his lifetime, the king actually offered two distinct prayers [מלבי״ם]. The first prayer was spoken while he was held in prison. This initial plea is considered an ordinary, non-sacred prayer; as a result, it was not included in the Holy Scriptures and was only preserved in external books. In contrast, after God answered him, Manasseh offered a second, holier prayer. This later prayer was documented by the prophets and ultimately included in the Book of Psalms.