Jumuah

Imaam pausing in the middle of the khutbah to make an announcement

Q: During the Jumu'ah Khutbah (the second Khutbah) the Imaam stopped in the middle of the Khutbah and made an announcement saying "whilst the Khutbah is on we are not allowed to talk". 

1. What is the ruling, will this nullify the Khutbah or not? 

2. What is the ruling with regarding to stopping the Khutbah to make an announcement? 

3. Will the Jumu'ah have to be made Qadha of?

Imaam standing on the Mimbar after the khutbah and making an announcement for straightening the saffs

Q: 

1. After the Khutbah on Jumu'ah, can the Imaam continue standing on the Mimbar to see that the Masjid is being filled and there are no spaces? 

2. After the Khutbah on Jumu'ah, can the Imaam continue standing on the Mimbar and make the announcement for straightening the Saffs? 

3. What is the ruling regarding waiting after the Khutbah on Jumu'ah to let the Masjid get filled?

Missing Jumuah Salaah

Q: If a male misses 3 jumuahs through work purposes but he had clarified it with his boss but had no one else to put in his place, what should he do concerning reading the shahaadat? The boss has promised that he will be getting a replacement.

Minimum number of people for Jumuah Salaah to be valid

Q: The masjid in our area is fairly new. We have, for Jumu'ah, about just over a dozen musallis. It is a mixed congregation of Shaafi and Hanafi. Our imaam for Salaah passed away in September. Since then, while we are looking into appointing a new Imaam, we have invited other Ulama to conduct Jumuah. 

The last imam who came, informed us that our Jumuah is problematic as per Imam Shaafi, there should be at least 40 men. 

Is it correct? Or can we continue with Jumuah Salaah?