Salaah

Altering one's sitting posture after sajdah to avoid urine drops coming out

Q: I have a problem that when I go to sajdah, some drops of urine come out. So when I do sajdah, I do my best to prevent from this happening. For this I often do sajdah with my feets not touching each other in sajdah. 

Also when I rise from one sajdah I do not sit properly and then again go to the next sajdah. 

These acts prevent the drop of urine from coming out. 

Is this permissible for me or not to do during Namaz?

Children standing in the adults' saffs if they are misbehaving

Q: Is it correct for a person to keep his sons behind him in the masjid - away from other children as these children are causing a disturbance in the back. Some children hit others. 

What will be the correct age to bring children to the masjid? Any guidelines regarding the children's saffs as some mention that the children can stand in the adults' saffs if they are misbehaving. 

Please clarify with guidelines for our masaajid.

Moving one saff back for an Aalim to stand in the first saff for salaah

Q: When we are in the masjid and iqaamah has already started, sometimes a person in the first row moves back to make space if another learned Maulana arrives, even though there are already a few learned Ulama present in the first row. 

Should we move from our place to give space to a Maulana at that time, or should we remain focused and avoid movement so we can prepare ourselves to stand before Allah? What is the correct adab according to the sunnah?