Is it permissible to pray after eating food that has been defiled by impurity, and does a person remain impure even if he washes his mouth, due to the impurity remaining inside the body?

It is not permissible to intentionally consume impure substances, as they are among the forbidden foul things, except out of necessity. The Ummah has reached a consensus on the impermissibility of consuming impurities. As for the effect of consuming impurities on prayer, some jurists have stipulated that the prayer of one who has eaten or drunk an impure substance is invalid as long as it is in his stomach and he is able to vomit it out. Otherwise, it does not affect the validity of his prayer due to his inability.