1 The Hebrew term הוֹי (hoy, “woe, ah”) was used in funeral laments and is often prefixed to judgment oracles for rhetorical effect. But here it appears to be a simple interjection, designed to grab the audience’s attention. Perhaps there is a note of sorrow or pity. See 223
2 The statement is an oxymoron. Its ironic quality adds to its rhetorical impact. The statement reminds one of the norm (one must normally buy commodities) as it expresses the astounding offer. One might paraphrase the statement: “Come and take freely what you normally have to pay for.”

In other versions

“Come, everyone who thirsts,

come to the waters;

and he who has no money,

come, buy and eat!

Come, buy wine and milk

without money and without price.

“Come, all you who are thirsty,

come to the waters;

and you who have no money,

come, buy and eat!

Come, buy wine and milk

without money and without cost.

“Come, everyone who is thirsty,

come to the water;

and you without silver,

come, buy, and eat!

Come, buy wine and milk

without silver and without cost!

“Is anyone thirsty?

Come and drink—

even if you have no money!

Come, take your choice of wine or milk—

it’s all free!

“Ho! Everyone thirsty, come to the waters!

And whoever has no money, come, buy and eat,

and come, buy without money,

wine and milk without price!

Ho, every one that thirsteth, come ye to the waters,

And he that hath no money;

Come ye, buy, and eat;

Yea, come, buy wine and milk without money and without price.

Public Domain