in this mountain - Zion: Messiah’s kingdom was to begin, and is to have its central seat hereafter, at Jerusalem, as the common country of “all nations” (Isa 2:2, etc.).
all people - (Isa 56:7; Dan 7:14; Luk 2:10).
feast - image of felicity (Psa 22:26, Psa 22:27; Mat 8:11; Luk 14:15; Rev 19:9; compare Psa 36:8; Psa 87:1-7).
fat things - delicacies; the rich mercies of God in Christ (Isa 55:2; Jer 31:14; Job 36:16).
wines on the lees - wine which has been long kept on the lees; that is, the oldest and most generous wine (Jer 48:11).