Ikhfa Letters: List of 15 Letters and How to Read Them in Tajwid
Ikhfa is a reading rule in tajwid that happens when nun sukun or tanwin meets one of 15 specific letters, so it's read vaguely, somewhere between clear and humming. The fifteen ikhfa haqiqi letters are: kaf (ك), qaf (ق), fa' (ف), zha (ظ), tha (ط), dhad (ض), shad (ص), syin (ش), sin (س), za' (ز), dzal (ذ), dal (د), jim (ج), tsa' (ث), and ta' (ت).
Ikhfa haqiqi is divided into three levels based on makhraj: ikhfa kubra (when met with ta', dal, tha'), ikhfa wustho (when met with 10 letters like tsa', jim, dzal, etc.), and ikhfa sughra (when met with qaf and kaf). Besides that, there's ikhfa syafawi, which occurs when mim mati meets the letter ba (ب).
In general, ikhfa is read with humming the sound (ghunnah) for 2-3 harakat and blurring the sound while adjusting to the makhraj of the next letter. Examples are in Surah Al-Falaq verse 2: مِن شَرِّ مَا خَلَقَ, and in Surah Al-Alaq verse 14: أَلَمْ يَعْلَم بِأَنَّ اللَّهَ يَرَىٰ.
https://mozaik.inilah.com/ibad