Siman 178

Partners who transported merchandise for which they must pay customs, and one of the partners requested of the customs official that he forgive him, and he forgave him—even if he said that he forgives him alone, it belongs to the partnership. Since he forgave him through his request, he is like their agent. And even if he requested that he forgive him alone, he acted improperly, since it is a partnership business, and therefore the profit belongs to everyone. But if the customs official on his own, without his request, said, "I forgive the portion of so-and-so," or if another man requested of the customs official on his behalf and he did not request that the man request on his behalf, it belongs to him alone. For everything a partner does and exerts effort toward belongs to the partnership, but that which comes to his hand without exertion is like a find. And all this is regarding a business of merchandise where the partners must still act further in the business, and therefore everything he exerted effort toward belongs to the partnership. But in a business of debt, such as where many people were indebted to one for a sum of money and one of them requested of the creditor that he forgive him his portion and he forgave him, the partners have no portion in this. For since afterwards no partnership remains for him with them, the name "partnership business" does not apply to this [Netivot HaMishpat]. And there are those who disagree even regarding a partnership business and hold that the forgiveness is for him alone even when it was through his exertion, for behold, this is like a find, and what is it to the partners if he exerted effort in this [Maharam of Rothenburg and the Maharshal]. And one whom the minister exempted from taxes, nevertheless, the needs of the community and the city are incumbent upon him as well, as was written in siman 163.

It has already been explained in siman 176 that a partner has the authority to act in the business as he sees fit for the benefit of the business when the second partner is not present. Furthermore, the Sages, of blessed memory, said that a partner who entered a field of the partnership and planted it, even if it was not intended for planting, takes according to the law of the sharecroppers of the city who enter with the permission of the owners, which will be explained in siman 375. A partner is considered as one who entered with permission. Moreover, he takes his full share even in the improvement that the plantings improved on their own, even at the time they were ready to be harvested. And even though in such a case a sharecropper's hand is at a disadvantage, as is written there, nevertheless the partner has the authority to act when he acts for the benefit of the partnership. The same applies if he deals without permission with a shared movable object; since he acted in the manner of merchants, his partner has no claim against him. All this is specifically if the improvement is greater than the expenditure, but if the expenditure is greater than the improvement and he spent from his own pocket and not from the pocket of the partnership, the partner only takes expenditure according to the improvement that was improved. If it did not improve at all, he takes nothing, for he should not have spent from his own pocket without the knowledge of his fellow. However, when he spent from the pocket of the partnership, the loss is upon the partnership, since he acted in the manner of merchants.

And all this is specifically in an ordinary case where the partner did not protest against him. However, if the second partner protested against him not to act—for example, if he built a building and the other protests against him—if it is a matter that must necessarily be built, such as if the house was dilapidated, his fellow is obligated to give his portion, for in such a case his partner has the power to compel him. But if it is not a necessity, his fellow may say to him: "Take your wood and your stones," and similarly in all matters [ibid.]. And this is the intention of our teacher, the Rema: