What is the ruling on marriage between a man and a woman who is older than him, or vice versa, in light of custom, traditions, and religion?

There is no harm in a man marrying a woman older or younger than him. The Prophet, peace and blessings be upon him, married Khadijah, may Allah be pleased with her, who was older than him, and he married Aisha, may Allah be pleased with her, who was younger than him.

It is desirable for there to be a closeness in age between spouses, as it generally fosters greater affection and love. However, if there is an overriding benefit that takes precedence over age proximity, then it is acceptable. Just as the Prophet, peace and blessings be upon him, did not agree to marry Fatimah to Abu Bakr or Omar, may Allah be pleased with them both, due to her young age, he married her to Ali, may Allah be pleased with him, because their ages were closer.

Closeness in age is considered important unless the husband possesses a virtue that compensates for the age difference. Thus, the Prophet, peace and blessings be upon him, married Aisha when he was over fifty years old, and she was six years old. And Ali, may Allah be pleased with him, had a greater virtue over Abu Bakr and Omar, may Allah be pleased with them both, concerning the marriage of Fatimah, which was his closeness in age to her, ensuring the continuity of affection and love.

In summary, closeness in age between spouses is desirable unless there is a valid reason that achieves the interests of marriage and affection.