Is a partner obligated to pay a portion of the profits from his private business to his other partner if he used a portion of the undistributed profits of their joint company as temporary liquidity for his private business, given his ability to return the amount at any time without affecting the other partner?

If two partners engage in a business and make a profit, it is not permissible for either of them to benefit from the other's money, borrow it, or invest it in their own trade without permission, due to the sanctity of another's property. If someone trades with another's money without permission and makes a profit, the profit is a matter of scholarly disagreement among the jurists: The Malikis and Shafi'is said that it belongs to the aggressor in exchange for his guarantee. The Hanbalis said that it belongs to the owner of the money. Abu Hanifa and Muhammad said that it should be given in charity. Sheikh al-Islam Ibn Taymiyyah chose that the profit should be shared between them, with the aggressor taking a share similar to that of a mudarib (investing partner), and being given a customary percentage of the profit, such as a half, a third, or a quarter, and the remainder going to the owner.