Is a person sinful if he utters a polytheistic phrase such as "what Allah willed and you willed" unintentionally? And does the ḥadīth "Indeed, a man may utter a word, not considering it significant, by which he falls into Hellfire" apply to him if it was unintentional? And what is your clarification of Allah's saying: (Our Lord, do not take us to task if we forget or make a mistake) and the ḥadīth: "My Ummah is forgiven for unintentional mistakes, forgetfulness, and what they are forced to do" in this context?

The command of the Messenger of Allah, peace and blessings be upon him, and the avoidance of his prohibitions are obligatory. If a forbidden utterance slips from the tongue unintentionally, its utterer should seek forgiveness and will not be held accountable, Allah willing, due to the Almighty's saying: "Allah does not burden a soul beyond its capacity," and the hadith: "My Ummah has been forgiven for mistakes, forgetfulness, and what they are compelled to do." There is no contradiction between this and the verse: "Our Lord, do not take us to task if we forget or make a mistake," for this is an acknowledgment of Allah's blessing. As for the word a person utters without giving it thought, which leads him to Hell, it is the word intended to slander a Muslim, or a word whose goodness or badness is unknown; therefore, one must guard their tongue.