But when Pharaoh saw is literally “And Pharaoh saw,” but most translations introduce when to emphasize he sinned yet again as the main verb phrase. Had ceased introduces the English pluperfect along with the relative when clause. The repeated reference to the rain and the hail and the thunder is natural in Hebrew narrative, but it may be condensed as in Good News Translation, “When the king saw what had happened.” Contemporary English Version has “When the king realized that the storm was over.”

He sinned yet again is literally “and he added to sinning.” And hardened his heart uses the verb meaning “to make heavy” (see the discussion at 4.21.) Note that here it is the king who causes his heart to become hard. He and his servants refers to the act of hardening the heart, not necessarily to the sinning. New International Version expresses it more naturally: “He and his officials hardened their hearts.”

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 .