When the thought is about Allah Himself
The Companions were asked this by their own minds. The Prophet ﷺ gave them a way out that does not involve arguing.
يَأْتِي الشَّيْطَانُ أَحَدَكُمْ فَيَقُولُ مَنْ خَلَقَ كَذَا مَنْ خَلَقَ كَذَا حَتَّى يَقُولَ مَنْ خَلَقَ رَبَّكَ فَإِذَا بَلَغَهُ فَلْيَسْتَعِذْ بِاللَّهِ، وَلْيَنْتَهِ
Satan comes to one of you and says: who created this, who created that, until he says: who created your Lord? When he reaches that, let him seek refuge in Allah and stop.
The instruction is not to answer the question. It is to stop having the conversation. Engaging is what the whisper wants.
The full narration
Narrated Abu Huraira:Allah's Messenger (ﷺ) said, "Satan comes to one of you and says, 'Who created so-and-so? 'till he says, 'Who has created your Lord?' So, when he inspires such a question, one should seek refuge with Allah and give up such thoughts
Source
Ṣaḥīḥ al-Bukhārī · 3276
- Agreed upon as authentic (al-Bukhārī / Muslim)