King James Version (KJV) - 2 Kings 10:6 >

Then he wrote a letter the second time to them, saying, If ye [be] mine, and [if] ye will hearken unto my voice, take ye the heads of the men your master’s sons, and come to me to Jezreel by to morrow this time. Now the king’s sons, [being] seventy persons, [were] with the great men of the city, which brought them up.

Berean Study Bible (BSB) - 2 Kings 10:6 >

Then Jehu wrote them a second letter and said: “If you are on my side, and if you will obey me, then bring the heads of your master’s sons to me at Jezreel by this time tomorrow.” Now the sons of the king, seventy in all, were being brought up by the leading men of the city.