Proclaim before him, i.e. cause this to be proclaimed, to wit, by some public officer appointed for that service. Compare Genesis 41:43.
Related Commentaries of Esther 6:9
Esther 6:9
9 And let this apparel and horse be delivered to the hand of one of the king's most noble princes, that they may array the man withal whom the king delighteth to honour, and bringd him on horseback through the street of the city, and proclaim before him, Thus shall it be done to the man whom the king delighteth to honour.