Pharaoh turned means that the king “turned away” from Moses and Aaron, and possibly from his own magicians as well. He had evidently been standing there beside the river with his officials while all this was taking place. Went into his house suggests that the palace was close to the river. But this is not clearly indicated, so Good News Translation has “he turned and went back to his palace.”

He did not lay even this to heart is another idiom meaning “without paying any attention even to this” (Good News Translation). The word for heart may also refer to the mind or the inner self. In 9.21 the same idiom, with a different word for lay, is rendered in Revised Standard Version as “did not regard,” and in Good News Translation as “paid no attention to.” Other possible renderings are he “dismissed the matter from his mind” (New English Bible), “taking no notice even of this” (New Jerusalem Bible), and “paying no regard even to this” (New Jewish Publication Society’s Tanakh).

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 .