Is the money saved by the applicant, after receiving financial assistance from someone who treats him like a father to meet his needs, lawful or unlawful?

If a man gives you money as a donation, willingly and out of his good heart, and he does not intend for it to be spent on a specific purpose, then there is no harm for you to benefit from it for any permissible purpose, or to save it. However, if he specifies the purpose of the money, then it must be spent on that purpose. It is disliked to ask people for their money unless there is a necessity or a severe need.