A while ago, I have seen a question and your response on this website regarding a hamzah with a tiny circle (zero), but was..

Assalam u alaikum,

A while ago, I have seen a question and your response on this website regarding a hamzah with a tiny circle (zero), but was unable to locate this. Please, if you would, point me towards this Q&A. I have seen hamzah like this that appeared after a wow which was preceded by a Dhammah letter. During the recent Hajj I met an Arabic speaking person who told me that this hamzah is called Hamzatul Jam’aa. And also, what is the purpose of this hamzah? Is there anything to do with not dropping the wow (long vowel) when stopping here? Hope the question is clear enough. 

As always, thank you for your great help. Jazak Allah.

Wassalam u alaikum.

 Answer

Wa alaikum assalaam wa rahmatullahi wa barakatuh,

The following links of previous question and answers should give you the information you need.

http://www.abouttajweed.com/080702.htm

http://www.abouttajweed.com/061103.htm

The alif you refer to is referred to as alif tafreeq, or a separating alif.  The first link explains the zeros and the second link explains this alif and its zero.  As indicated in the answer in the second link, this alif is not pronounced and has no grammatical place.  It is written after the  to show the end of the word.  The  that precedes this alif is can  jama3, or plural .  

Wa iyyaakum. Wa assalaam alaikum wa rahmatullahi wa barakatuh.