Mom's Belongings After Her Death

Assalam o Allaikum everyone. This question is from a very dear friend of mine and I'll narrate as she did to me: > **"My mom recently died. We are 4 sisters in total and our father is still alive. Before her death, mom made 4 portions of her gold > belongings, wrote our names on each of them and told everyone to open > them after her death. Now when she died our father told us to take > those gold portions as per the name written on them.** > > **The issue arose when my brother-in-law told a mufti about it and now he is forcing us all to return the gold to our father as our mom only > verbally told us but not in writing. I want to know even when my mom > told in front of everyone that who should keep her belongings then why > does this mufti say that her words don't matter anymore because she is > dead."** Please assist me with this one. Thank You.