Exodus 9:14

“For I will at this time send all my plagues upon thine heart, etc.] 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 by them are not meant all the plagues that were in the power of God to inflict, which how many and great they are none can say, but all that he had determined in his mind to bring upon him; and these should not so much affect and afflict his body, as the boils and ulcers had the magicians, but should reach his heart, and fill…”

“With the plague of hail begins the last series of plagues, which differ from the former both in their severity and their effects. Each produced a temporary, but real, change in Pharaoh’s feelings. Exodus 9:14 All my plagues - This applies to all the plagues which follow; the effect of each was foreseen and foretold. The words “at this time” point to a rapid and continuous succession of blows. The plagues which precede appear to have been spread over a considerable time; the first message of Moses was delivered after the early harvest of the year before, when the Israelites could gather stubble, i. e. in May and April: the second mission, when the plagues began, was probably toward the end of…”

“I will find all my plagues upon thy heart - Hitherto thou hast not felt my plagues on thy own person, the heart is put for the whole man. Exodus 9:16”

“9:14-17 God explained the purpose of the plagues to Pharaoh: They were revelatory, designed to demonstrate (especially to Pharaoh) that there is no one like me in all the earth (9:14; see also Isa 46:9; Jer 10:6-7). God had not destroyed Pharaoh and Egypt in a single blow, as he could have done. Rather he had spared them (Exod 9:16), giving them an opportunity to submit to his power. But Pharaoh refused to humble himself and stop lording it over the Lord’s people (9:17).”

“send all: Lev 26:18, Lev 26:21, Lev 26:28; Deu 28:15-17, Deu 28:59-61, Deu 29:20-22, Deu 32:39-42; Sa1 4:8; Kg1 8:38; Jer 19:8; Mic 6:13; Rev 18:8, Rev 22:18 that thou: Exo 8:10 Exodus 9:15”