Revoking of Settlement/Gift Deed given by my Father

I am a Muslim. only son to my father and my age is 35. My father is at 62. My father bought properties from my Mom dowry jewels in 1985 before he was nothing. My mother was expired 6 years before. I am married and with 2 childerens. Since he is not comfortable with us and needs companion, He is planing for second marriage now. He genuinely requested myself and my wife to come forward and conduct the same. But I made one condition to accept that he(my father) should settle his properties to me to avoid all legal issues in future with his future companion. Then he too agreed to execute and registered a Deed of Gift (Settlement) on my name with no conditions. But now he got one companion, we came forward and have arranged him for second marriage which is going to be held next month. But after he got second companion and marriage dates are fixed. Now he is threatening me that he wants the original registered document to proceed with legal action against me to cancel the settlement deed.