I think Pentecost does well making the point the Palestinian covenant is in addition to the Mosaic covenant. Deuteronomy 29:1 makes it clear that Moses is laying forth the details of the agreement under which the people would enter the land of Palestine in addition to the Mosaic covenant given at Horeb (Sinai).
Pentecost also made a strong point portraying the idea that although the conditional Mosaic covenant followed the unconditional Abrahamic covenant, it did not negate the original promise of the land in the Abrahamic covenant. I found it especially strong when he cited Galatians 3:17. The Ryrie NAS Study Bible Genuine Leather Black Red Letter (Ryrie Study Bibles 2012) supports this view as well. Ryrie wrights “The Mosaic Law did not set aside the promises made to Abraham.” And we can know Paul is referring to the Mosaic Law because of his reference to 430 years, which can be traced back to Ex. 12:40.
When I first read the point from Chafer that Pentecost affirms about how Deut. 30:3-6 relates to the return of the Messiah, I did not see that in the text. I could see that Israel will be restored to the land and converted as a nation, but the relation to the coming Messiah did not become clear until I read this explanation:
“However, Israel’s repentance would be insufficient to reverse the effects of their curses for they would still be under foreign domination. So in response to their repentance, God Himself will intervene, and with tender compassion … gather the nation and bring her back to her land. He will restore Israel’s fortunes, a theme frequent in the prophets (cf., e.g., Jer. 30:18; 32:44; 33:11, 26; Joel 3:1). The prophets made it clear that this great restoration to the land would not take place until the Second Advent of the Messiah just before the beginning of His millennial reign on the earth (e.g., Isa. 59:20–62:12; cf. Jesus’ teaching of the regathering in Matt. 24:31; Mark 13:27). This will be a time of spiritual and material prosperity greater than the nation has ever known (Deut. 30:5).
30:6. The promise that the Lord your God will circumcise your hearts (cf. 10:16) means that God will graciously grant the nation a new will to obey Him in place of their former spiritual insensitivity and stubbornness. After returning to the Promised Land with a new heart they will remain committed to the Lord and therefore will experience abundant blessing (live). Loving Him wholeheartedly (cf. 30:16, 20; see comments on 6:5), they would not fall back into apostasy as they had done before. A new heart is an essential feature of the New Covenant (cf. Ezek. 36:24–32), which will not be fulfilled for Israel as a nation until the return of Jesus Christ (cf. Jer. 31:31–34).”
I also find it a strong point that Pentecost affirms Chafer’s point about Deut. 30:7 predicting the judgement of Israel’s enemies. The Ryrie NAS Study Bible Genuine Leather Black Red Letter (Ryrie Study Bibles 2012) also points out the relation of this text to Joel 3:1-2, which also points to Matt. 24:31, 25:40 and 45.
Furthermore, Pentecost makes a very strong point when he states (above) that “God considers Israel’s relation to the land vitally important” because we see this very clearly in the Abrahamic covenant recorded in Gen. 15:18-21.
Pentecost’s reference of Ezekiel 16 being prophecy that has to do with the Palestinian covenant is also a strong point. The Ryrie NAS Study Bible Genuine Leather Black Red Letter (Ryrie Study Bibles 2012) has commentary that goes right along with Pentecost’s, which also affirms Deut. 28-30: “This chapter depicts Israel as an unfaithful wife (cf. Hose. 1-3; Jer. 2; Isa. 1:21, 50:1). Her sin is described in verses 3-34, her punishment in verses 35-52, and her restoration in verses 53-63.”
Understanding that Ezekiel 16 is tied to the Palestinian covenant, Pentecost makes a strong point about the conditionality of the covenant. He points out that God describes the covenant as “everlasting”. If it is going to be everlasting, then no conditions could exist, because if conditions are not met then the covenant would be nullified.
Pentecost’s fourth point on conditionality is strong in the regard that the covenant is unconditional because of the already partial fulfillment of the covenant. He also overlooks a point that the restoration depends on the nation’s conversion, which the text clearly says God will do (Deut. 30:6). Therefore, if God will do it because he of his sovereignty and integrity, then the covenant is not conditioned upon the people.
 Charles Caldwell Ryrie, The Ryrie NAS Study Bible Genuine Leather Black Red Letter (Ryrie Study Bibles 2012), (Chicago: Moody Publishers, 2011), 235.
 Ibid. 1431.
 Jack S. Deere, “Deuteronomy,” in The Bible Knowledge Commentary An Exposition of the Scriptures by Dallas Seminary Faculty 2 Volumes Old & New Testament, ed. J. F. Walvoord and R. B. Zuck, vol. 1 (Wheaton, IL: Victor Books, 1985), 315.
 Charles Caldwell Ryrie, The Ryrie NAS Study Bible Genuine Leather Black Red Letter (Ryrie Study Bibles 2012), (Chicago: Moody Publishers, 2011), 1059.
 Ibid. 972.