Eldad and Medad means in the bible: Two elders were among the 70 who helped Moses out of danger in the wilderness. These two elders are listed because they were given the gift prophecy by Moses in connection to their calling. They didn’t get the appointment to the tabernacle. Moses asked Joshua to prohibit them from prophesying, but Moses replied, “Would God all the Lord’s people be prophets and that the Lord would place his spirit upon them.” Num. 11:24-29.
(in Bible Dictionary)
