Is it a sin to conceal the documents and the installment amount for paying the second installment of the land plot, with the intention of teaching the two brothers responsibility and fulfilling one's word?

If one of the partners wishes to sell a property that cannot be divided except with damage or requires compensation, then everyone is compelled to sell. If one of them refuses, the ruler sells it and divides the price among the partners according to their shares. Any partner who wishes to buy has the right of pre-emption (shufa'a). Sheikh al-Islam Ibn Taymiyyah holds the view that whatever cannot be divided in kind should be sold and its price distributed. Division is of two types: consensual division (qismat taradin), which, if it results in damage or requires compensation, is not concluded except with the consent of all partners. If one refuses to sell in such a case, the ruler compels him to do so, and its sale is considered equivalent to a sale. It is not permissible to hide its documents or money. The second type is compulsory division (qismat ijbar), which applies if it does not result in damage or require compensation; in this case, the refusing partner is compelled to accept it.