Mem without Harakah
Mem Sakinah (مْ) has three different states:
a) When Mem Sakinah is followed by a Mem with a harakah, then Idghame Methlayn Ma’al Gunna occurs. Mem sakinah is pronounced with a ghunna (nasal sound):
عَلَيْهِمْ مُؤْ صَدَةٌ
b) When Ba (ب ) follows Mem Sakinah, the Ikhfa (hiding) occurs. The sound of Mem Sakinah is hidden in pronounciation:
اِنَّ رَبَّهُمْ بِهِمْ
c) When Mem Sakinah is followed by any letter except Ba and Mem, then Izhar occurs. The pronounciation of Mem Sakinah is exposed clearly:
مَعَكُمْ اِنَّمَا