God has put it into their hearts to carry out his purpose: the expression “to put into the heart” means to cause someone to decide, resolve, purpose. Here it is God who will make these ten kings decide to do what will actually be God’s own plan, even though they are not aware of this. Without their knowing it, they will be God’s instrument for achieving his purpose. So one may translate “God has caused them to decide….”

Being of one mind and giving over their royal power to the beast: as in verse 13.

Until the words of God shall be fulfilled: this condition, in which the ten kings will let the beast rule over them, will last until all of God’s purposes and plans are achieved. Here the words of God has the specific meaning of what God, through his messengers, has said will happen in the End. For the verb “fulfill” see 10.7.

Alternative translation models for this verse are:

• The ten kings will do this because God has caused them to decide to do what he wants them to do. And so they will all agree to surrender their royal power to the beast. They will obey the beast until all of God’s purposes are completed.

Or:

• … and so they will all agree (or, have a united heart [or, mind]) and let the beast have their power to rule as kings. They will obey the beast until God has caused all his plans to be completed (or, come to fruition [or, bear fruit]).

Quoted with permission from Bratcher, Robert G. and Hatton, Howard A. A Handbook on The Revelation to John. (UBS Handbook Series). New York: UBS, 1993. For this and other handbooks for translators see here .