Let us come before his presence - פניו panaiv, his faces, with thanksgiving, בתודה bethodah, with confession, or with the confession-offering. Praise him for what he has all ready done, and confess your unworthiness of any of his blessings. The confession-offering, the great atoning sacrifice, can alone render your acknowledgment of sin and thanksgiving acceptable to a holy and just God.

let us

Psalm 7:7 So shall the congregation of the people compass you about: for their sakes therefore return you on high.

Psalm 100:2,4 Serve the LORD with gladness: come before his presence with singing...

Jeremiah 31:12,13 Therefore they shall come and sing in the height of Zion, and shall flow together to the goodness of the LORD, for wheat, and for wine...

come before his presence. Heb. prevent his face

Psalm 17:13 Arise, O LORD, disappoint him, cast him down: deliver my soul from the wicked, which is your sword:

Psalm

Psalm 105:2 Sing to him, sing psalms to him: talk you of all his wondrous works.

James 5:13 Is any among you afflicted? let him pray. Is any merry? let him sing psalms.

Covenanting a Duty.
The exercise of Covenanting with God is enjoined by Him as the Supreme Moral Governor of all. That his Covenant should be acceded to, by men in every age and condition, is ordained as a law, sanctioned by his high authority,--recorded in his law of perpetual moral obligation on men, as a statute decreed by him, and in virtue of his underived sovereignty, promulgated by his command. "He hath commanded his covenant for ever."[171] The exercise is inculcated according to the will of God, as King and …
John Cunningham—The Ordinance of Covenanting

Psalms
The piety of the Old Testament Church is reflected with more clearness and variety in the Psalter than in any other book of the Old Testament. It constitutes the response of the Church to the divine demands of prophecy, and, in a less degree, of law; or, rather, it expresses those emotions and aspirations of the universal heart which lie deeper than any formal demand. It is the speech of the soul face to face with God. Its words are as simple and unaffected as human words can be, for it is the genius …
John Edgar McFadyen—Introduction to the Old Testament