Jamieson, Fausset and Brown on 2 Thessalonians 1:9

9. Who--Greek, "persons who," &c.

destruction from the presence of the Lord--driven far from His presence [Alford]. The sentence emanating from Him in person, sitting as Judge [Bengel], and driving them far from Him (Mt 25:41; Re 6:16; 12:14; compare 1Pe 3:12; Is 2:10, 19). "The presence of the Lord" is the source whence the sentence goes forth; "the glory of His power" is the instrument whereby the sentence is carried into execution [Edmunds]. But Alford better interprets the latter clause (see 2Th 1:10), driven "from the manifestation of His power in the glorification of His saints." Cast out from the presence of the Lord is the idea at the root of eternal death, the law of evil left to its unrestricted working, without one counteracting influence of the presence of God, who is the source of all light and holiness (Is 66:24; Mr 9:44).