What is the ruling on saying: "Something is destined for us, and it is destined for us to part with people"? What is the ruling on saying: "Long live whoever heard your voice"? And what is the ruling on saying: "Haram عليك (It is forbidden for you)" concerning something that is not forbidden?

The first statement is true, for Allah has written everything in the Remembrance, as stated in the verse: "Do you not know that Allah knows what is in the heaven and earth? Indeed, that is in a Book. Indeed, that, for Allah, is easy." As for the second phrase, "May Allah prolong your life for those who hear your voice," it is a permissible supplication, carrying no objection. It means a prolonged life so that the listener may hear his voice after an absence, so there is no harm in it. As for the third phrase, its ruling has been discussed in a previous fatwa (definition).