C. F. Keil and Franz Delitzsch on Isaiah 26:2

Isa 26:2

In Isa 26:1 this city is thought of as still empty: for, like paradise, in which man was placed, it is first of all a creation of God; and hence the exclamation in Isa 26:2 : “Open ye the gates, that a righteous people may enter, one keeping truthfulness.” The cry is a heavenly one; and those who open, if indeed we are at liberty to inquire who they are, must be angels. We recall to mind Psa 24:1-10, but the scene is a different one. The author of Ps 118 has given individuality to this passage in Psa 118:19, Psa 118:20. Goi tzaddik (a righteous nation) is the church of the righteous, as in Isa 24:16. Goi (nation) is used here, as in Isa 26:15 and Isa 9:2, with reference to Israel, which has now by grace become a righteous nation, and has been established in covenant truth towards God, who keepeth truth ('emunim, from 'ēmūn, Psa 31:24).