Today’s text has a two-fold purpose – both a call to worship and a warning.

The psalmist begins with an invitation to join together in worship (vv. 1-2).  This is not the worship of a dutiful soul, but of a joyful one.  The psalmist is not worshipping because he has to, or someone expects him to; rather, he is worshipping because he wants to be there, and joyfully invites others to join him.

While verses 1-2 identify the “what” and “how” of worship, verses 3-5 focus on the “why”:  the greatness of God.  Our God is above all other idols (small “g” gods), period.  He is the creator of the heavens and the earth, including the mountains, the depths of the earth, the seas, and everything in between.

So what is our response to the awesomeness of God?  humility – of both heart and body (v. 6-7a).  Remember that the position of the body reflects the attitude of the heart.  Bowing our heads and getting on our knees is not a magic formula, but rather, the full acknowledgment that God is sovereign and we are putting ourselves under Him.

Verses 7b – 9 are the psalmist’s warning to not repeat the sins of their ancestors in the days of Moses.  The psalmist refers specifically to the episode at Rephidim (Exodus 17:1-7).  The Lord was leading His people through the desert using Moses as His spokesperson.  When the Lord had the people stop at Rephidim, there was no fresh water to drink.   Rather than trusting the Lord and asking for His provision, the people argued with Moses and hardened their hearts against the Lord.

In fact, Moses gave two names to this place – “Meribah” (quarreling) and Massah (testing).   Both of these names reflected sins against the Lord; testing God (Massah) and arguing with the Lord’s anointed servant Moses (quarreling) were both ultimately reflecting on the hardness of their hearts toward God.

The writer of Hebrews provides clear commentary and application of this psalm:

3 Therefore, holy brothers and sisters, who share in the heavenly calling, fix your thoughts on Jesus, whom we acknowledge as our apostle and high priest. ² He was faithful to the one who appointed him, just as Moses was faithful in all God’s house. ³ Jesus has been found worthy of greater honor than Moses, just as the builder of a house has greater honor than the house itself. ⁴ For every house is built by someone, but God is the builder of everything. ⁵ “Moses was faithful as a servant in all God’s house,” bearing witness to what would be spoken by God in the future. ⁶ But Christ is faithful as the Son over God’s house. And we are his house, if indeed we hold firmly to our confidence and the hope in which we glory.

⁷ So, as the Holy Spirit says:

“Today, if you hear his voice,
⁸     do not harden your hearts
as you did in the rebellion,
    during the time of testing in the wilderness,
⁹ where your ancestors tested and tried me,
    though for forty years they saw what I did.
¹⁰ That is why I was angry with that generation;
    I said, ‘Their hearts are always going astray,
    and they have not known my ways.’
¹¹ So I declared on oath in my anger,
    ‘They shall never enter my rest.’ ”

¹² See to it, brothers and sisters, that none of you has a sinful, unbelieving heart that turns away from the living God. ¹³ But encourage one another daily, as long as it is called “Today,” so that none of you may be hardened by sin’s deceitfulness. ¹⁴ We have come to share in Christ, if indeed we hold our original conviction firmly to the very end.¹⁵ As has just been said:

“Today, if you hear his voice,
    do not harden your hearts
    as you did in the rebellion.”

¹⁶ Who were they who heard and rebelled? Were they not all those Moses led out of Egypt? ¹⁷ And with whom was he angry for forty years? Was it not with those who sinned, whose bodies perished in the wilderness?¹⁸ And to whom did God swear that they would never enter his rest if not to those who disobeyed? ¹⁹ So we see that they were not able to enter, because of their unbelief.
(Hebrews chapter 3 NIV, underlines mine)