Yechiel Michel Epstein,
Translation:Arukh ha-Shulchan…
“ That's why a person cannot legally bequeath property to someone who is not an heir (Chapter 6, Laws of Inheritance) . The reason seems to stem from the words 'a decree of judgment', which also gives him the Biblical right to increase the portion of one heir and decrease the portion of another (as explained the Rambam, chapter 6 and later in chapter 281) . This is also a type of inheritance and is like an act of the court that requires daytime. Therefore, if two visit a sick person and he does not wish to change the Torah mandated default distribution he need do nothing. ”
