Ash-shafatān designates the lips.
They constitute, in human body, with the buccal resonator, and the nasal resonator, one of the three places of sound resonance.
At the exit of the buccal canal, if the lipsare projected forward and rounded, the third resonator is formed: the labial resonator.
By rounding the lips forward and raising the bottom of the tongue towards the posterior part of the palate we produce the sound و (Wa), which corresponds to the english sound /u/ like in the word "true".
By gluing the lips, one creates an occlusion zone which produces the sound ب (Ba), which corresponds to the enblish /b/ like in the word "Brother".
By sticking the lips and accompanied by the "the nose sound" or "nasalization", one obtains the sound م (Miim), which corresponds to the sound /m/ like in the word "mother" in english, but with a longer and more reinforced
Finally, with the end of the upper incisorson the inside of the lower lip, the sound ف(Fa) is produced, which corresponds to the sound /f/ like in the word "father" in english.