NASB 1995
"When he sees riders, horsemen in pairs, A train of donkeys, a train of camels, Let him pay close attention, very close attention."

American Standard Version
and when he seeth a troop, horsemen in pairs, a troop of asses, a troop of camels, he shall hearken diligently with much heed.

Berean Study Bible
When he sees chariots with teams of horsemen, riders on donkeys, riders on camels, he must be alert, fully alert.”

Douay-Rheims Bible
And he saw a chariot with two horsemen, a rider upon an ass, and a rider upon a camel: and he beheld them diligently with much heed.

English Revised Version
and when he seeth a troop, horsemen in pairs, a troop of asses, a troop of camels, he shall hearken diligently with much heed.

King James Bible
And he saw a chariot with a couple of horsemen, a chariot of asses, and a chariot of camels; and he hearkened diligently with much heed:

World English Bible
When he sees a troop, horsemen in pairs, a troop of donkeys, a troop of camels, he shall listen diligently with great attentiveness."

Young's Literal Translation
And he hath seen a chariot -- a couple of horsemen, The rider of an ass, the rider of a camel, And he hath given attention -- He hath increased attention!

Isaiah 21:7 Additional Translations ...