Is it permissible for a woman to marry after the death of her husband, to whom she made a vow that she would not marry after him, and would that be considered a breach of the vow?

It is permissible for a woman to marry after the death of her husband, and she must expiate for her oath, because the Prophet, peace and blessings be upon him, said: "By Allah, if Allah wills, I will not swear an oath and then see something better than it, but I will expiate for my oath and do that which is better." And his saying: "If you swear an oath and then see something else better than it, then expiate for your oath and do that which is better." And marriage is better for a woman than remaining without it.