I will freely sacrifice unto thee: I will praise thy name, O LORD; for it is good.
I will freely sacrifice unto thee. "Freely" - literally, 'with a freewill offering' х nªdaabaah (H5071)] (Exodus 25:2; Exodus 35:29), distinguished from an offering which one was bound to pay, as ordained by the law, or as having vowed it in trouble (Leviticus 7:15-16). It answers in parallelism to "I will praise thy name."
For it is good - namely, to "praise thy name" (Psalms 52:9, note; 92:1)