But he who did not regard refers to those “officials” of the king who were not the “fearers” described in verse 20. The phrase literally reads “and who did not set his heart unto the word of Yahweh.” This is the same idiom used in 7.23, where it is said of the Pharaoh, “and he did not lay his heart even to this.” (Different verbs are used, “set” and “lay,” but the meaning is the same.) It simply means that “Others, however, paid no attention” (Good News Translation); that is, they “disregarded” (Jerusalem Bible), “ignored” (New International Version), the word of the LORD. As explained earlier, this refers to the “warning” of Yahweh in 9.13-19, as it does in verse 20.

Left here means “left alone” in the sense of not even disturbing them. His slaves and his cattle refers to the slaves and livestock belonging to the officials, not to the king. In the field means “out in the open” (Good News Translation), in contrast with verse 20.

Quoted with permission from Osborn, Noel D. and Hatton, Howard A. A Handbook on Exodus. (UBS Helps for Translators). New York: UBS, 1999. For this and other handbooks for translators see here .