Salaam alaikum. I need you to answer this question as if it doesn’t contain a single error or unclarity in its description. He doesn’t have the intention to sin or offend Allah. His only intention is the imagining of that voice. I am saying this because i have heard many people insulting Allah with nasty words which are shown with punctuations or beeps in the media. And i have a phobia that simply remembering or recalling or bringing to mind their insulting voices, puts you beyond the pale of islam or is kufr size sin. If someone makes the intention to imagine the voice of someone who has insulted Allah in a very nasty manner. With nasty I mean very dirty words of a thug or hooligan or barker. Words that are shown with punctuations ….. in the media because they cannot be shown to the public. And after making the intention he imagines that voice as if he is hearing it right now word by word. What is the level of sin? His only intention is the imagining of that voice. Don’t confuse with waswas. Because waswas are for example: I am staying idle and suddenly a bad thought that offends allah comes to my mind. In this case he has the intention of imagining that voice word by word as if he is hearing that voice at that moment. But his only intention is the imagining of that voice. He doesn’t have the intention to sin or offend Allah.