Seeing Jannah while in this world

Q: 

1. It is said that no eye has seen Jannah, so if people say they have seen Jannah in a dream, what is the case here? 

2. If someone feels that they have had a vision of Jannah in a state of being awake and they see someone wearing a white garment, could they have seen Jannah because in the Quran it is described that the people of Jannah will have green clothing? Can one know for sure if they have seen a vision of Jannah?

Distributing one’s inheritance during one’s lifetime

Q: My father wants advice regarding his will. 

He wants to know if he gave his sons their shares while he was alive, does he needs to include the sons in the will if they have received their shares already? He has not given his daughter's their shares yet, only the sons. 

And is the ruling the same regarding the distribution of assets for the father and mother to the children in the will?

Circumcision for a revert adult Muslim

Q: I wanted to ask for some guidance regarding circumcision for a revert. 

Is it fardh for an adult revert to undergo circumcision, or is it considered sunnah? I am particularly concerned about the medical risks involved, such as possible infection and bleeding, especially as an adult. 

How should someone in this situation approach the matter, balancing religious obligations with health considerations? Are there circumstances where it can be delayed or excused?

Marrying one's milk sister

Q: I wanted to marry a girl but later they told me that her mother breastfed me once when I was less than one year. I researched about it and according to my knowledge in Quran it is forbidden to marry but there is no evidence of how many times of breastfeeding is required. From hadith I found that there is one hadith from Hazrat Aaisha (radhiyallahu anha) which states that five breastfeeding is required to make it haram. Please guide me regarding this issue.

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.