What are the rulings of marriage in the religion, and how can the suitor be persuaded to postpone the marriage until next summer?

Marriage should not be delayed except for a valid reason, as the Prophet, peace and blessings be upon him, said: "There are three things that should not be delayed: Prayer when its time comes, a funeral when it is present, and a woman without a husband (or a single woman) when a suitable match is found." If you wish to delay it, you can convince the groom by explaining the reason for the delay or by mediating through a person of influence with him.