Why is heathcliff so eager for cathy and linton to marry before edgar dies?

Answer:

Heathcliff so eager for Cathy and Linton to marry before Edgar dies so that she can help him rise and leave her brother’s power.

Explanation:

Heathcliff is one of the main fictional character in the famous novel Wuthering heights, who is mostly known for his romantic situation with his lover Catherine Earnshaw. However, regardless of his strong feelings, Heathcliff insisted that Cathy and Linton marry and this is due to several reasons.  

Around the half of the novel, the character of Heathcliff started changing and developed into an angry, disturbed, unhappy and hostile man. Therefore, the first idea that came into Cathy’s mind was helping him by marrying Lincoln before the death of Edgar. By that, Edgar could use his connection to aid her true lover Heathcliff instead of marrying him as she had no money and having no future with him.