How sound is the Hadith: "O Moses, Pharaoh sought your help seventy times, and you did not help him; had he sought My help once, I would have helped him"?

This narration attributed to Ibn Abbas, which is mentioned by Al-Tabari, Ibn Abi Hatim, and Al-Baghawi in their interpretations, is likely taken from the Isra'iliyyat (Jewish traditions). Al-Razi has highlighted its weakness and stated that one should dispense with such stories in favor of what is authentically established, because they do not provide certainty. Therefore, it is preferable to discard it and suffice with what the text of the Qur'an indicates.