Bruce Waltke writes of the reference to land in these verses:
Were this the law and the prophets, it would undoubtedly refer to the LORD’s land grants to his covenant people in Canaan. But in the wisdom literature, which treats humanity apart from Israel’s historic covenants, ‘eres more likely refers to the ground in general with its fatness (Gen. 27:28), in- crease (Lev. 26:4, 20), and fruit (Num. 13:20); as such it is a metonymy for life.83 The good earth stands in striking contrast to the grave with the dead (2:18-19). [Waltke, NICOT, 1:234]
Walkte’s rationale for distinguishing this passage from the law and the prophets is not sound. Verse 16 referred to the Jewish adulteress (note that v. 17 refers to the true God as her God) as a foreign woman (using two different terms for foreign) as a way to indicate that her adultery was contrary to the covenant expectations that marked out the Israelites. Given this context, the reference to the land should be seen as a link between Proverbs and the Law and the Prophets. This does not mean that the connection between land and life is incorrect. The land promises anticipated eternal life in the land.
Bered Schipper is more correct when he’s sees clear connections between this passage and Deuteronomy (something that characterizes these opening chapters in Proverbs):
These people are now told that they will inhabit (שׁכן) the land or “remain” (יתר niphal) in it. It was noted above … that the topic of dwelling in the land is a central part of Deuteronom(ist)ic theology (see Deut 4:1; 5:16; 25:15; and 2:22: Commentary).121 If Israel keeps the commandments, it may dwell in the land (cf. Exod 20:12). [Schipper, Herm., 120]
He also notes connections to the prophets:
the combination of the verb יתר niphal (“to remain”) and the preposition בְּ (“in”), which also occurs in Isa 4:3 and Ezek 14:22.122 Both of these texts connect the verb יתר niphal (“to remain”) with the concept of the “remnant” of Israel. The statement in Prov 2:21 is also similar to Isa 60:21, where the “righteous” (צַדִּיקִים) are promised that they will possess the land (ירשׁ אֶרֶץ) in perpetuity.123 Thus, it is quite possible that Prov 2:21 contains eschatological overtones, as has sometimes been suggested. [Schipper, Herm., 120]
