How is Idghaam properly pronounced?

Question

Al-Salaamu Alaykum

I have a question regarding Idghaam. How is Idghaam properly pronounced?
For example, in Surah Saff Verse 5, it says
, do you pronounce this Idghaam by saying
 
"", pronouncing it as the daal is a taa with sukoon, or by saying "", pronouncing it as the daal with a sukoon, and then the taa with a fathah.

Jazaakallahu Khayran

Answer

Wa alaikum asslaaam wa rahmatullahi wa barakatuh,
In an idghaam, there is one letter merging into a second letter, in this process when it is a complete idghaam the first letter merges into the second so that it becomes the second letter, and that is why the second letter acquires a shaddah on it.
In the question example the daal of merges into the
’ so that what we pronounce is a with a shaddah on it and no is pronounced at all. So what we pronounce is: , the same way as the first of the two possibilities in the question. 

Wa iyyaakum

Wa assalaam alaikum