Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
quran:20:7 –

And if you speak aloud - then indeed, He knows the secret and what is ˹even˺ more hidden.  

And should you be loud in your speech, in remembrance ˹of God˺ or supplication, then God has no need for this to be ˹spoken˺ loud, then indeed He knows the secret and ˹that which is˺ yet more hidden, than that ˹secret˺, namely, that which the soul whispers ˹to itself˺ and that which occurs to the mind but which you do not speak of ˹to anyone˺, so do not strain yourself to be loud ˹in your speech˺.
القرآن:٢٠:٧ –

وَإِنْ تَجْهَرْ بِالْقَوْلِ فَإِنَّهُ يَعْلَمُ السِّرَّ وَأَخْفَى  

{وإن تجهر بالقول} في ذكر أو دعاء فالله غني عن الجهر به {فإنه يعلم السر وأخفى} منه: أي ما حدثت به النفس وما خطر ولم تحدث به فلا تجهد نفسك بالجهر.