“For the teraphim have spoken wickedness.” The teraphim were household gods, and they were sometimes consulted by various means of divination as we see here in Zechariah 10:2, when the teraphim “speak” (see commentary on Gen. 31:19). The Hebrew word translated “wickedness” is aven (#0205 אָוֶן), the common meanings of aven include trouble, wickedness, and sorrow. The Brown, Driver, and Briggs Hebrew Lexicon gives the meaning of “thoughts of trouble” and “wicked imaginations” for the definition of aven in Zechariah 10:2, which makes perfect sense. The teraphim were idol gods and were an abomination to God. When they were consulted it was not God who answered through them, but demons, and those demons gave wicked advice and led people away from God. Consulting idols is a lose-lose situation. If the demons think they can get away with giving evil and harmful advice they do, and cause trouble for those who ask for answers from them. On the other hand, if the demons give good advice then people trust them and are pulled deeper into idolatry and disobedience to God which always has bad consequences. [For more on demonic practices that believers are not to be involved in, see Deut. 18:9-14].
“there is no shepherd.” There were no godly leaders. Here, as in many other places, “shepherds” refers to the leaders (see commentary on Jer. 2:8).