Question

Assalamu alaykum wa rahmatullah

In one of your lessons, you explained: "Whenever a saakinah letter comes before a voweled letter of the same articulation point and characteristics, in other words the same exact letter, there is merging of the saakinah letter into the second letter. This merging is called ... small merging of two of the same" (Ex: Quraysh 4 ). 

I also see similar mergings, with close letters but not the same exact letter (Ex1: in Al-Kafirun, Verse 4: " " "maa abattum" is formed from "ma abad tum"; Ex2: Aali Imraan: 72: "wa qaalattaaifatun" the merging here seems to be from qaalat and taaifatun). I wonder whether these cases form a different type of merging, or whether they actually obey the same rule that you explained.
Jazakum Allah khayran.
Aassalamu alaykum wa rahmatullah

Answer

Wa alaikum assalaam wa rahmatu Allahi wa barakatuhu.  Masha’ Allah you are a very observant student of the Qur’an.  May Allah increase your knowledge and make you of “ahl al-Qur’an”, roughly translated as “people of the Qur’an.”

There are three categories of , or merging.  The first is the definition you quoted from the site: Whenever a saakinah letter comes before a voweled letter of the same articulation point and characteristics, in other words the same exact letter, there is merging of the saakinah letter into the second letter.  This is called  or merging of two of the same.

The second category is when there are two letters that share the same articulation point, but do not share all the same characteristics.  The rule in this second case is not an absolute rule, meaning there are certain letters that have the same articulation point, but do not share all the same characteristics, and if the first is saakin and the second is voweled, they merge.  This is called , or merging of two similar in nature.  The examples you gave in your question of aayah 4 of Al-Kaafiroon , and aayah 72 of Aali ‘Imraan  are both of this category.  The letters that share articulation points, but not all the characteristics and merge into one another if the first is saakin and the second voweled are as listed below, with the top letter merging into the bottom:

The third category of idghaam is when the two letters are close in articulation point or characteristics.  Again, as the previous category, it is not  an absolute rule, but one that is only for certain letters.  The same conditions exist for idghaam to occur in this category, the first letter must be saakin and the second voweled.  This category is called: , or merging of two close in nature. .  The merging of the  saakinah with the letters of idghaam , except the  (which would be ) is in this category.  The letters that  saakinah merges into other than the itself are in this category.  This includes the  shamsiyyah letters, as well as the merging of the  saakinah and the .  Also in this category is the merging of the  into the  in one place in the Qur’an: . 

Wa iyyakum.  Wa assalaam alaikum wa rahmatu Allah wa barakatuhu