No matter what you dream, dreams are just your subconscious reaction. In other words, in the dream, your late father asked you to buy a cow for your mother. In this dream, your late father is actually just your subconscious, yourself, not your real father. So what does this dream mean? We can understand it from this angle. If the cow symbolizes labor in the countryside, then it has a symbol of strength in the family. Belonging to the head of the family, the pillar, actually refers to men. In your subconscious, you think that a family needs a man who symbolizes masculine strength. Only in this way can the burden of family be borne and life be more like life than loneliness. As for the significance of becoming a father in a dream, on the one hand, it is to set off his kindness and infinite love for his family, on the other hand, it is hoped that this is the recognition, understanding and support from his father.
Summary: This is a very rational dream.