This is a Divorce that Does Not Count

Question :

I said to my wife: "If you give the boy (i.e. my son) money from my personal money, you will be divorced. And what I meant by that was to encourage her not to give any sum to the boy, because he would use it to bring women who play the Duff for his wedding and I refuse this, due to the financial situation in which I live; and I have helped him as much as I can in his marriage, but as for the things which are secondary to the essentials of marriage, or the luxuries of marriage, I cannot provide them. And it was not my intention there by to divorce my wife. I request your advice.

Answer:

If the intention was to prevent her from giving him anything of your money and it was not the intention to pronounce divorce if she did that, then you must make atonement for an oath if she gave him anything, according to the most authoritative of two views held by the scholars, and she must turn to Allah in repentance.

This is because it is not permissible for her to disobey your command in a matter such as this; rather, it is incumbent upon her to hear and to obey in all reasonable things. And we advise you not to repeat a divorce like this. May Allah set right both your situations.

Source:
Ibn Baz
Fatawa Islamiyah, Vol. 6 Page 58