Jamieson, Fausset and Brown on Zechariah 13:2

2. Consequences of pardon; not indolence, but the extirpation of sin.

names of ... idols--Their very names were not to be mentioned; thus the Jews, instead of Mephibaal, said Mephibosheth (Bosheth meaning a contemptible thing) (Ex 23:13; De 12:3; Psa 16:4).

out of the land--Judea's two great sins, idolatry and false prophecy, have long since ceased. But these are types of all sin (for example, covetousness, Ep 5:5, a besetting sin of the Jews now). Idolatry, combined with the "spirit" of "Satan," is again to be incarnated in "the man of sin," who is to arise in Judea (2Th 2:3-12), and is to be "consumed with the Spirit of the Lord's mouth." Compare as to Antichrist's papal precursor, "seducing spirits ... doctrines of devils," &c., 1Ti 4:1-3; 2Pe 2:1.

the unclean spirit--Hebrew, spirit of uncleanness (compare Re 16:13); opposed to "the Spirit of holiness" (Ro 1:4), "spirit of error" (1Jo 4:6). One assuming to be divinely inspired, but in league with Satan.