What is the ruling of Islamic law regarding a brother expelling his brother from work without prior notice, and not giving him the previously agreed-upon end-of-service bonus?

Resolving disputes falls under the purview of the judiciary or its representative, because it hears from all parties and issues a well-founded ruling, whereas a mufti (definition) hears only from one party. As for end-of-service benefits, if stipulated in the contract or established by custom, they are part of the wage and must be paid; otherwise, they are an unbinding gift. Regarding termination of employment, a distinction is made between fixed-term contracts (ijarah (definition) muḥaddadah al-mudda), which must be fulfilled, and open-ended contracts (al-mushāharah), which either party may terminate unless the lessee has paid the rent or the new month has begun.