27. know that I am in the midst of Israel--As in the Old Testament dispensation God was present by the Shekinah, so in the New Testament first, for a brief time by the Word made flesh dwelling among us (Joh 1:14), and to the close of this dispensation by the Holy Spirit in the Church (Mt 28:20), and probably in a more perceptible manner with Israel when restored (Eze 37:26-28).
      never be ashamed--not an unmeaning repetition from Joe 2:26. The twice-asserted truth enforces its unfailing certainty. As the "shame" in Joe 2:26 refers to temporal blessings, so in this verse it refers to the spiritual blessings flowing from the presence of God with His people (compare Jer 3:16, 17; Re 21:3).

JFB.