Holman Christian Standard Bible because an angel would go down into the pool from time to time and stir up the water. Then the first one who got in after the water was stirred up recovered from whatever ailment he had.
International Standard Version At certain times an angel of the Lord would go down into the pool and stir up the water, and whoever stepped in first after the stirring of the water was healed of whatever disease he had.
American Standard Version for an angel of the Lord went down at certain seasons into the pool, and troubled the water: whosoever then first after the troubling of the waters stepped in was made whole, with whatsoever disease he was holden.
Young's Literal Translation for a messenger at a set time was going down in the pool, and was troubling the water, the first then having gone in after the troubling of the water, became whole of whatever sickness he was held.