1.

I will sing of mercy and judgment: unto thee, O LORD, will I sing.

I will sing of mercy and judgment: unto thee, O LORD, will I sing.
I will sing — I will praise thee, O Lord, for thy mercy and justice, which thou hast so eminently discovered in the government of the world, and of thy people; and I will make it my care to imitate thee herein.

2.

I will behave myself wisely in a perfect way. O when wilt thou come unto me? I will walk within my house with a perfect heart.

I will behave myself wisely in a perfect way. O when wilt thou come unto me? I will walk within my house with a perfect heart.
I will — I will manage all my affairs with wisdom and integrity.
When — God is often said in scripture to come to men, when he fulfills a promise to them.
House — In my court and family, as well as in my public administrations.

3.

I will set no wicked thing before mine eyes: I hate the work of them that turn aside; it shall not cleave to me.

4.

A froward heart shall depart from me: I will not know a wicked person.

A froward heart shall depart from me: I will not know a wicked person.
Depart — Shall be turned out of my court.
Know — Not own nor countenance.

5.

Whoso privily slandereth his neighbour, him will I cut off: him that hath an high look and a proud heart will not I suffer.

6.

Mine eyes shall be upon the faithful of the land, that they may dwell with me: he that walketh in a perfect way, he shall serve me.

7.

He that worketh deceit shall not dwell within my house: he that telleth lies shall not tarry in my sight.

8.

I will early destroy all the wicked of the land; that I may cut off all wicked doers from the city of the LORD.

I will early destroy all the wicked of the land; that I may cut off all wicked doers from the city of the LORD.
Early — Speedily; as soon as I am seated in the throne.