Conversion to meem

The mechanic

Before ب, the noon or tanween is turned into a hidden meem: the lips come together lightly and the nasal sound is held on it. The mushaf prints a small meem over the noon (U+06E2), or under it for kasratan (U+06ED).

Where it occurs

The letter that triggers it, and how the mushaf marks it

ب

• ۢU+06E2
• ۭU+06ED

A place in the text

وَمَا تَفَرَّقَ ٱلَّذِينَ أُوتُواْ ٱلۡكِتَٰبَ إِلَّا مِنۢ بَعۡدِ مَا جَآءَتۡهُمُ ٱلۡبَيِّنَةُ

The marked spot was located in this ayah's own text at build time — Al-Bayyinah 98:4.