But: This conjunction contrasts the sparing of the children of the assassins after the assassins themselves were executed. Most languages will require a similar transition word marking this contrast.

The children of the murderers refers to the children of the officials mentioned in the previous verse who had been involved in the assassination of King Joash.

According to … the book of the law of Moses … “The fathers shall not be put to death for the children … but every man shall die for his own sin”: Exo 20.5 declares that God punishes the children for the sins of their fathers. The punishment for the sin of Achan in Josh 7.25 seems to confirm this. But it is Deut 24.16 that is quoted here. This verse focuses on individual responsibility for sin. In this passage the word translated fathers is not intended to limit the meaning to the male parents. It is for this reason that certain modern versions use the word “parents” (Good News Translation, New Revised Standard Version, Revised English Bible, New Jerusalem Bible, New Century Version). Similarly, every man is intended to refer to “every person” and not exclusively to males.

Quoted with permission from Omanson, Roger L. and Ellington, John E. A Handbook on 1-2 Kings, Volume 2. (UBS Helps for Translators). New York: UBS, 2008. For this and other handbooks for translators see here .