Is there a connection between my refusal of a suitor from the army due to his old age and my saying that I reject this destiny, and the delay in my marriage? What can I do to atone for that, and is there a supplication to facilitate marriage?

If the suitor is a person of good religious practice and character, he should not be rejected merely due to a difference in age, as long as it does not reach the point of senility, following the example of the Prophet's marriage (peace be upon him) to Khadijah and Aisha (may Allah be pleased with them). The questioner's statement, "If this were my destiny, I would reject him," is impermissible, as it implies an objection to Allah's decree. Her feeling of guilt is an indication of her remorse, which is a form of repentance, and Allah accepts repentance and pardons sins. Her lack of marriage may be due to other sins from which she has not repented, so she must repent and become righteous. There is no specific supplication for facilitating marriage, but there are comprehensive supplications for the good of this world and the Hereafter.