Answered by Shaykh Yusuf Weltch
How do I know if I’m purposefully bringing these thoughts to mind? Can I perform Dhikr in my mind while performing salaah (in silent prayers)? Please respond to that. Alhamdulillah, I intend to pray properly before salaah. But what if I don’t understand what’s being said, or even if I do, I still drift off? I’ve also noticed that I keep saying bad duas, which I despise.
Is this Waswas? Would I be held responsible? How do I fight misgivings that cause me to make bad supplications?
In the Name of Allah, the Most Merciful and Compassionate
Doing remembrances in the prayer is an emphasized sunna action during the bowing and the prostration. The Messenger of Allah (may Allah bless him and give him peace) is described, “He used to say ‘Subhana Rabbiya’l A’zim’ (Glory to my Lord, Almighty) in his bowing and ‘Subhana Rabbiya’l A’ala’ (Glory to my Lord, Most High) in his prostration.” [Muslim]
To do remembrances in other places during the prayer does not invalidate the prayer, however, it is disliked (with the exception of the final one/two unit(s) of obligatory prayer). [Tahtawi/Shurunbulali, Hashiyat Maraqi al-Falah]
Misgivings: Bad Supplications
Know that you are not your thought and you are not accountable for these involuntary thoughts, regardless of them being in the prayer or outside of the prayer. Ignore them as best as you can. See this for more helpful details:
How to Attain Presence of Heart in Prayer
Hope this helps
Allah knows best
[Shaykh] Yusuf Weltch
Checked and Approved by Shaykh Faraz Rabbani