For it was of the LORD to harden their hearts to engage Israel in battle, so that they would be set apart for destruction and would receive no mercy, being annihilated as the LORD had commanded Moses.
KJV
For it was of the LORD to harden their hearts, that they should come against Israel in battle, that he might destroy them utterly, [and] that they might have no favour, but that he might destroy them, as the LORD commanded Moses.
ASV
For it was of Jehovah to harden their hearts, to come against Israel in battle, that he might utterly destroy them, that they might have no favor, but that he might destroy them, as Jehovah commanded Moses.