How sound is the statement that our Prophet Muhammad (peace be upon him) forgot to say "Insha'Allah" (if God wills) because God made him forget it in order to teach him and to teach the Companions, based on the interpretation of the verse: "And never say of anything, 'Indeed, I will do that tomorrow,' except [by adding], 'If Allah wills.' And remember your Lord when you forget, and say, 'Perhaps my Lord will guide me to what is nearer than this to right conduct'"?

The mention of forgetfulness in the Quran and Sunnah indicates that it is permissible for prophets to experience it, as happened to Solomon (peace be upon him) and the Prophet Muhammad (peace be upon him). The texts should be taken at their face value, and it is not permissible to deviate from them except with evidence. His (peace be upon him) forgetfulness was for a wisdom, so that believers may emulate him in rectifying what they forget. This is part of Allah's complete favor upon the Ummah and the perfection of the religion. As for the claim that the Prophet is infallible from forgetfulness, it is false and contradicts the texts, and it is not valid to deduce the negation of forgetfulness from him based on his continuous worship.