Ikhfaa Haqiqi is one of Noon sakinah and Tanween rules,At the first let’s revise Noon sakinah and Tanween rules, there are four rules:
1- Izhar halqi    ( إظهار حلقي )
2- Idgham ( with and without ghunna). ( إدغام بغنة  و بغير غنة )
3- Ikhfaa Haqiqi      ( إخفاء حقيقي )
4- Iqlab ( إقلاب )

• Meaning of Ikhfaa:

Ikhfaa means to hide the sound of some letters but not cancel these letters, plus making Ghunaa ( Nasal sound which comes out of the Gill ).

• Ikhfaa Haqiqi letters :(حروف الإخفاء الحقيقي)

Ikhfaa letters are all letters other than letters of Izhaar  ( ء , هـ , ع , ح, غ , خ ), lqlaab (ب) or ldghaam ( ي , ن , م , و ), about fifteen letters for Ikhfaa Haqiqi. This rule can be happen in one word like ( مَنصُوراَ )or two words like (  مِن صِيامٍ ).

• Method of Ikhfaa Haqiqi pronunciation:

If any letter other than the letters of Izhaar, lqlaab or ldghaam follows Noon Saakinah or Tanween, the reader shall hide the Noon Saakinah or Tanween and make ( Ghunnah  of two beats or seconds).

The correct way  to pronounce the lkhfaa is to place your tongue at the point of articulation of the lkhfaa letter and pronounce the Ghunnah of two beats .

The rule in brief:

 Noon sakinah or Tanween + Ikhfaa letter —> You should apply Ikhfaa + ghunna (for 2 seconds).

Types of Gunnah for Ikhfaa:

Ikhfaa Gunnah is classified into two types:

1- heavy ghunna.

2-light ghunna.

If the Noon Saakinah or Tanween is followed by a heavy letter ( ص , ض , ط , ظ , ق ) the sound of Ghunnah should also be heavy. If the Noon Saakin or Tanween is followed by a light  letter, the sound of Ghunnah should also be light.

• Examples of Ikhfaa:

( من قبل )

(مِنْ سِجِّيلٍ)

(  سِجِّيلٍ* فَجَعَلَهُمْ)

(كُتُبٌ قَيِّمَةٌ)

What is the difference between Ikhfaa Haqiqi and Ikhfaa shafawi?

Ikhfaa shafawi rule is related to Meem sakina ( Meem sakinah + baa letter ب )

Ikhfaa Haqiqi rule is related to Noon sakinah and Tanween + one of fifteen letters which mentioned above.

In this video, one of our teacher explain this rule in details here