How was David able to give to him all Sha'ul's property?
Rashi: A king can transfer inheritance and give to his servants. 1
Refer to 9:7:2:2,4.
Why would David do so? Sha'ul had seven other descendants, that the Giv'onim killed later (21:6)! Perhaps they were like Mored b'Malchus (refer to 9:7:2:2. - PF)