Is it permissible to acquire lands that their owners abandoned for more than 20 years in a disputed area, in exchange for a sum of money to build upon them?

It is not permissible for officials to grant disputed land to expatriates and residents unless a just judicial ruling confirms that neither party owns it, in which case the state has the right to dispose of it. If ownership is proven for one of the parties, then that party alone has the right to dispose of it, and no other party, whether the state or individuals, may dispose of it unlawfully, for Allah Almighty says: "And do not consume one another's property unjustly" [Quran 2:188], and the Prophet, peace and blessings be upon him, said: "Indeed, your blood, your properties, and your honor are sacred among you." And: "Whoever wrongfully takes a span of land will have it encircled around his neck from seven earths." Therefore, it is not permissible for your husband to help anyone acquire these lands, as it is assisting in sin, and Allah Almighty said: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression." [Quran 5:2].