Does divorce occur due to the whispering of Satan, or due to bringing to mind the intention of divorce when reciting the verse, "And if you want to replace a wife," with the aim of verifying a previous intention, knowing that the questioner does not desire divorce?

What you are experiencing is a type of waswas (whispers/obsessive thoughts). Do not pay attention to it so that it does not overpower you and become difficult to get rid of. If it comes to your heart, seek refuge with Allah from Shaytan, the accursed. The fundamental principle regarding marital inviolability is its ثابت (permanence), and it does not cease merely due to doubt, because what is established with certainty cannot be removed except by an equal certainty. For this reason, jurists have stipulated that the divorce pronounced by someone afflicted with waswas does not take effect.