That is because God would never change a grace that He had conferred on a people, to the end [of the verse]: in other words, all that reaches man is [only] that which his preparedness entails and what he requests by the supplications of his state and by the requesting of is deserved [by him]. Thus when He confers upon a person an outward or an inward grace by virute of the soundness of [his] preparedness and the remainder of goodness in him, He does not change it until that [person] corrupts his preparedness and changes his receptivity for righteousness by veiling himself and by the transmutation of the good that is in him in potentiality into evil because of the actualisation of rust [on his heart] and the accumulation of darkness therein, such that there no longer remains in him any correspondence to good nor any possibility for it to issue from him, whereupon He will change that [grace] into a disfavour, as an act of justice and generosity from Him and in response to the demand made for it by that preparedness by virtue of the attraction in terms of genus and correspondence, and not out of any injustice or tyranny [on His part].