Moses
Exodus 9:14ESV·traditional attribution

For this time I will send all my plagues on you yourself, and on your servants and your people, so that you may know that there is none like me in all the earth.

John Calvin Reformed @genevareformer

14. For I will at this time. The unexpressed condition is implied, “unless he should submit himself to God.” The meaning is, that although he had already chastised his pride, yet that this had been done gently and in moderation; but that He now would use a heavier scourge, since the lighter rods had been unavailing.

Matthew Henry Presbyterian @wholebiblehenry

Here is, I. A general declaration of the wrath of God against Pharaoh for his obstinacy. Though God has hardened his heart (Exo 9:12), yet Moses must repeat his applications to him; God suspends his grace and yet demands obedience, to punish him for requiring bricks of the children of Israel when he denied them straw.

Commenting on Exodus 9:13-21

John Gill Reformed Baptist @doctorgill

For I will at this time send all my plagues upon thine heart,.... Not meaning particularly the plague of the hail, which next follows, so called, because it consisted of various things, as hail, rain, lightning, and thunder, as Aben Ezra, and who observes, that Pharaoh was more terrified with this plague than with any other; but rather all the plagues yet to come, for...