Matthew Poole and continuators on Exodus 9:14

14 For I will at this time, send all my plagues upon thine heart , and upon thy servants, and upon thy people: that thou mayest know that there is none like me in all the earth.

Or, into thy heart: Thou hast hitherto not felt my plagues upon thy own person, or thy body, but I shall shortly reach and wound it, and that not onely in the skin; as the magicians and others are now smitten▪ but even to thy heart, such as shall make thy heart sick, Mic. 6. 13. such as shall give thee a mortal and irrecoverable wound. Some understand it of inward and spiritual judgments upon Pharaohs heart, such as hardness of heart. But that plague had been inflicted upon him, and is recorded before this time. And Pharaohs heart being here opposed to his servants and people seems rather to denote his person, the heart or soul being often put Synecdochically for the whole man.