Gift - Cash or House

What is the name of your state (only U.S. law)? Maryland
I would like to give to my married child cash gift approx. 300k to purchase house. I am concerned that in the case of divorce 1/2 of the house might belong to the ex-spouse of my child.
or,
I can firstly purchase the house in my name, let the married child family live in the house and ultimately bequeath the house to the own child only (and/or his siblings). Do I create myself a tax problem? I'm living long distance from the children and often stay with them in the house.

If you are concerned with his wife becoming his ex-wife and getting money than you should consider your motivations for this gift more carefully.

300K is a LARGE gift and you really need a lawyer to craft the agreement you want with minimal tax or divorce consequences.

I will say personally that this strikes me as terribly controlling of your son and disrespectful of his family.

Bottom line, get a lawyer. Be prepared for your 'gift' to cause terrible tension. Unless your son and wife are some kind of mental feebs... they will see your controlling and pathological behavior that seeks to play son against wife.