1)
What is the meaning of "ha'Medaber Elayich"?
1.
Radak: If someone from the family speaks to you [about killing your son or taking the inheritance], bring him to me!
2.
Malbim: I agree about you - you need not reveal to your family where your son is, and I will not investigate [whether you must reveal to me, to kill him based on a king's power, for I agree that there is no need to do so here]. However, the family may kill him if they find him.
2)
Why did he say "v'Haveiso"? One who commands a female should say v'Haveisiv!
1.
Radak: One of the king's youths who were standing there [when David said this] will bring him. She cannot bring him!