Assalaamu alaykum. What should one do if one makes a slip of the tongue in prononcing certain phrases? For example: if a person accidentally says "Alhamdulilaah" (praise be to Allah) incorrectly and then realizes soon after, are they obliged to repeat themselves with the correct pronunciation? If they are not obliged to do so, would it be better to repeat themselves? I ask because I know that Allah is Al-'Aleem (the All-Knowing), so when I correct myself, I get the feeling that I do not trust in Allah's infinite knowledge.

All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

Firstly, you should know that the Muslim bears no sin for what he may say with mistakes in pronunciation, because mistakes are pardoned. Allah, the Exalted, says (what means): {...And there is no blame upon you for that in which you have erred but (only for) what your hearts intended. And ever is Allah Forgiving and Merciful.} [Quran 33:5]

Ibn ‘Abbaas reported that the Prophet, sallallaahu ‘alayhi wa sallam, said, "Allah has pardoned my nation their mistakes and forgetfulness and what they are forced to do (under duress)." [Ibn Maajah]

One does not have to repeat what he said with mistakes in pronunciation, and there is no harm in repeating his statement correctly, and this does not imply mistrust in the infinite knowledge of Allah.

We noticed from your previous questions that you suffer from Waswaas (obsessive whisperings), which urges a person to ask this kind of questions and makes him exaggerate simple matters. Our advice to you is to strive to ignore this Waswaas and refrain from asking such questions that may enhance these obsessive whisperings in your mind.

May Allah keep us and you safe from every evil in this worldly life and the Hereafter.

Allah knows best.