The keepers of secrets, the seal of the mouth, the produces of baa’, meem, waaw and faa’ … you’ve only one option: stash away that lipstick, ladies, and beautify your lips with the letters of the Qur’aan!
Al-Shafataan: the lips are the makhraj (point of articulation) for four letters. There are two main areas within this makhraj; they are as follows.
Between The Two Lips
Maa baynal-shafataan  from between the two lips emerge the following letters,
Baa’ ( ب ), pronounced “bb”
Meem ( م ), pronounced “mm”
Consonant waaw ( و ), pronounced “wa” or “wi” or “wu” or “w”
It is important to note that the waaw being referred to is not the waaw maddeeyyah; which means it is the waaw with a fat-ha such as in the word
or the waaw with a dammah, such as in the word
or the waaw with a kasrah, such as in the word
or the waaw with a sukoon, such as in the word
The letters baa’ and meem emerge from pressing the lips together. However, the consonant waaw emerges by opening the lips slightly and bringing in the sides to form an “o” shape.
The Bottom Lip and Upper Incisors
The bottom lip, alongside the lower tips of the two front teeth produce the letter
Faa’ ( ف ), pronounced “ff”
These four letters ( ب و م ف ) are all named Al-Ahruf Al-Shafaweeyah  because they emerge from the shafataan, i.e. the lips.
These makhaarij are nearly over. So far we’ve covered four of the five main makhaarij “areas”, and a total of 16 of the 17 specific points of articulation. 🙂
– Makhaarij Al-Huroof document
Note, this document is found on the resources page.
 ما بين الشفتان
 الأحرف الشفوية