Meaning of the Prophet’s words “There should be no uncertainty (ghiraar) and no greeting in prayer”

His wudoo’ was invalidated after saying the tasleem to his right; is his prayer valid or must he repeat it?

If a woman did not cover her feet when praying, out of ignorance, does she have to repeat her prayer?

Does carrying a child on whom there is some najaasah (impurity) render the prayer and wudu invalid?

He notices the taste of toothpaste when he is praying. What should he do about food remnants that remain between his teeth? Is his prayer invalidated by swallowing his saliva?

Should he interrupt his prayer in order to answer one of his parents if they call him?

Is it permissible to make a player-place in which women will be in front of the imam?

Advice to one who deliberately makes a praying person laugh and distracts him from his prayer by talking to him

Does hesitating about stopping the prayer cancel it out?

How to understand the hadeeth when the prophet instructed the one who prayed badly to repeat his prayer and not ordering Mu’awiyah to repeat it?