Hume was almost certainly aware of the relevant Newtonian passage because Hume discusses the proper meaning of 'attraction' with explicit appeal to Newton's intentions in EHU 7.1.25
Newton's intentions(Hume's interpretation of Newton's meaning)
What Newton meant or tried to communicate when he wrote about a scientific concept—in this case, what he intended 'attraction' to mean.
Newtonian
"Newtonian" refers to ideas and laws developed by Sir Isaac Newton, a famous English scientist from the 1600s. It describes the traditional way we understand how objects move and interact through forces—for example, why a ball falls down when you drop it or why pushing something makes it move faster. Newton's ideas were so successful at explaining the physical world that "Newtonian" became the foundation of physics for over 200 years, though modern physics has since refined his theories for extreme situations like very fast speeds or tiny particles.
attraction(Newtonian mechanics; Hume's interpretation of Newton)
A term used by Newton whose proper meaning Newton explicitly clarifies in the Scholium following Proposition 69, Book I, Section 11 of the Principia; discussed by Hume in EHU 7.1.25
Hume’s ninth rule also has Newtonian debts. Since the time of Aristotle, many philosophers have asserted proportionality between cause and effect in one fashion or another. Hume’s ninth rule echoes, for instance, a principle Leibniz uses quite frequently: the principle of the equality of cause and effect. It is the basis of arguments Leibniz gives for his conservation principles (e.g., Specimen Dynamicum). But Leibniz’s formulation is in terms of equality and not proportionality. Unlike Leibniz