John Gill Commentary Esther 3:11

"And the king said unto Haman, The silver is given to thee, the people also, to do with them as it seemeth good to thee." — Esther 3:11 (ASV)

And the king said to Haman, the silver is given to you ,
&c.] The 10,000 talents of silver Haman proposed to pay into the treasury were returned to him, or the king out of his great munificence refused to take them:

the people also, to do with them as seems good to you ;
that is, the people of the Jews; he gave him full power to do with them as he thought fit, and who breathing revenge upon them, would not spare them.