Will a Muslim be rewarded for financially assisting his brother who is about to get married if he intends the reward and recompense from Allah, and not charity?

If your brother is in need of assistance, then helping him with that money is considered a charity for which you will be rewarded, and its reward is greater than helping others, as the Prophet, peace and blessings be upon him, said: "Charity given to a poor person is charity, and charity given to a relative is two things: charity and maintaining kinship ties." However, if he is not in need, then giving him money is considered a gift for which you will be rewarded for your good intention and for maintaining your kinship ties.