Labial Concealment (Ikhfa Shafawi) — Meem Saakinah Before Ba

Definition:
Labial Concealment (Ikhfa Shafawi): concealing the Meem Saakinah before the letter Ba, while maintaining the nasal resonance (Ghunna). Called "labial" because both Meem and Ba are articulated from the lips.

Rule:
When Meem Saakinah is followed by Ba from another word: Ikhfa Shafawi is obligatory — pronounce Meem with a concealed nasal sound (Ghunna) without fully closing the lips as in full assimilation (Idgham), and without the clear articulation of Izhaar.

Quranic Example:
"And they of the Hereafter are certain" [Al-Baqarah: 4] — Meem of "hum" is concealed before Ba of "bil-akhira".
"That you stand firmly for justice" [An-Nisa: 135] — Meem of "taqumu" concealed before Ba.

Note:
Ikhfa Shafawi is intermediate between Idgham and Izhaar: lips do not fully close, and the Ghunna lasts two counts. It is among the subtlest rulings of Meem Saakinah.