Question

There is a question among us regarding the formation of the leen letters:  we have read in the book of Tajweed Rules of the Qur'an that the leen letters as well as the medd letters are formed by vibration in the vocal chords.  One teacher thought that she had learned that they were emitted by either pressing on the makhraj of Ya for the ya leeniya or by the rounding of the lips in the case of the wow leeniya which would mean that they are pronounced by  (that is by collision) of the articulation parts.  We would be grateful if you could please enlighten us in this matter insha’ Allah.

Answer

There are two states for (the leen).  In one case there is a leen letter followed by one or more letters in the same word, and we are not stopping on the word with a medd leen.  This is called a leen letter.  In this case, there is a weak , or collision, between the two parts of articulation in addition to vibration of the vocal cords in the throat.   There would be then some mild pressure during the collision on the two lips in the case of the  (its articulation point), and pressure on the articulation point of the  when performing the collision of this letter, but the vibration of the vocal cords overwhelms the formation of the sound of the leen letter. 

The second case of leen is when there is a leen letter, meaning or    saakinah with a fath before it, there is only one voweled letter following it, and we are stopping on the word.  This is medd al-leen, which is lengthened 2, 4, or 6 vowel counts.  In the case of medd al-leen, the mechanism of formation is the same as the medd letters: vibration of the vocal cords with the accompanying circling of the lips for the  leeniyah, and lowering of the jaw for the  leeniyah. 

Insha’ Allah this makes things clearer.