In the thirty and eighth year - Rather, according to the previous numbers 2 Kings 14:23; 2 Kings 15:2, the 27th year of Azariah. Some suppose an interregnum between Jeroboam and Zachariah, which, however, is very improbable.
Matthew Henry
Concise Bible Commentary
This history shows Israel in confusion. Though Judah was not without troubles, yet that kingdom was happy, compared with the state of Israel. The imperfections of true believers are very different from the allowed wickedness of ungodly men. Such is human nature, such are our hearts, if left to themselves, deceitful above all things, and desperately wicked. We have reason to be thankful for restraints, for being kept out of temptation, and should beg of God to renew a right spirit within us.
SDA Bible Commentary (limited)
Volume 1-7
8. Six months. Israel was now entering upon the last dark period of its history. King followed king in rapid succession, with assassinations being the usual practice of the times.