Quote 1
"Oh, damnation! I will have it back; and I'll have his gold too; and then his blood; and hell shall have his soul! It will be ten times blacker with that guest than ever it was before!" (13.63)
Hindley loses everything to Heathcliff but must partly blame his own weaknesses and indulgence. He aspires to rob Heathcliff of everything and, like a devil figure, even wants his soul.
Quote 2
"Take my colt, Gipsy, then!" said young Earnshaw. "And I pray that he may break your neck: take him, and he damned, you beggarly interloper! and wheedle my father out of all he has: only afterwards show him what you are, imp of Satan." (5.65)
Even as a child, Hindley sees Heathcliff as a threat to his inheritance. But it is actually the way he treats Heathcliff that creates the orphan's drive to steal the inheritance. If Hindley had accepted him, things might have gone differently.