Literary Devices – Shemot 10

• Tanakh Lab demonstrates that the most frequently appearing word in Shemot 10 is "ארץ" (land) while, relative to the rest of Tanakh, the most prevalent words are "ארבה" (locust) and "ברד" (hail).  As these plagues are the topic of the chapter, their prevalence is natural.  The repetition of the word "land", though, might serve to highlight the target of these plagues, which was not the Egyptian population but its land and agricultural produce.
• Articles  – See Patterns in the Plagues for discussion of various divisions of the plagues into groups of two, three or five based on similar characteristics or unity in purpose.  Several commentators assert that the plagues of locust and hail should be viewed as a pair, noting that both target the land and crops.

The roots "כבד" and "חזק" appear only three times altogether in the chapter, but might be key words throughout the narrative of the Exodus.

• Concordance – Using the concordance to trace the usage of both the verb and adjective "כבד" in Torah¹ reveals how it appears throughout the Exodus narrative, marking key points in the story, from the initial "heavy" famine that causes the nation to descend to Egypt to the "great" wealth with which the nation leaves Egypt.²  Similarly, both the adjective and verbal root "חזק" repeat in the narrative, referring on one hand to Paroh's obstinance in preventing the Exodus and on the other to God's mighty hand which brings it about.
• Articles – See Prof. Yonatan Grossman's Leitwort who discusses the phenomenon of keywords as a whole, bringing "כבד" as one example, and R. Nathaniel Helfgot שתי מילים מנחות בסיפור יציאת מצרים, who explores the usages of the two roots כבד and חזק.  Both authors note how the repetition of the roots demonstrates Hashem's measure for measure actions during the Exodus.³

In a few places in this chapter, the Torah includes plays on words that highlight the contrast between the devastation of Egypt and the salvation of Israel, as power shifts from Paroh to Hashem’s agent Moshe: 

• Dr. Robert Alter, in his commentary on the Torah, points out a play between Hashem's words to the nation regarding Hashem's wonders which are to be told by the Israelites forever: “so that you shall recount to your son and your son’s son” (verse 2) and the severity of the plagues that befall Egypt: “the likes of which your fathers and your fathers’ fathers have not seen” (verse 6).  
• Da'at Mikra and Dr. Robert Alter’s commentary on the Torah point out a punning  connection between Moshe's chastising of Paroh: “Until when will you refuse to humble yourself before me?” (verse 3) and Paroh's servants' complaints: “Until when shall this be a trap for us?” (verse 7).   

The following articles contain general discussion of wordplay in Tanakh:

• See Wordplay in Biblical Hebrew: An Eclectic Collection, by Gary A. Rendsburg, for exploration of various forms of Biblical wordplays.
• See Wordplay in Ancient Near Eastern Texts, by Scott B. Noegel, for a book-length treatment of the range of permutations of word plays in Tanakh and in other Ancient Near Eastern texts.⁴