Adam Clarke on Psalms 102:18

The people which shall be created - "The Gentiles, who shall be brought to the knowledge of salvation by Christ," as the Syriac states in its inscription to this Psalm: how often the conversion of the soul to God is represented as a new creation, no reader of the New Testament need be told. See Eph 2:10; Eph 4:24; 2Cor 5:17; Gal 6:15. Even the publication of the Gospel, and its influence among men, is represented under the notion of "creating a new heaven and a new earth," Isa 65:17, Isa 65:18.