“Sing praises to the Lord, who sits enthroned in Zion! Tell among the peoples his deeds!” – Psalm 9:11
This middle verse of this short psalm, authored by David, is echoed throughout the OT (Is 12:4; 1 Chro 16:8; Ps 18:49, 96:3, 105:1). It is a call to sing praises of the works of God, not simply to the elect of Israel, but to all the ignorant nations. The chosen race of Israel already knew of God’s greatness. The majesty and grace of the Lord had been passed down from generation to generation, within God’s favored nation. It was the proclaiming of God’s greatness to the gentiles and pagans which was here being sought.
No doubt, the appealing for God’s people to proclaim him to the unknowing and unwilling cultures was a difficult task. Like today, those who do not know God, do not always receive his messengers with great joy. Making the lost aware of their sin and neediness is not always received with appreciation. John Calvin stated, “To proclaim God’s doings among the nations was indeed, as it were, to sing to the deaf; but by this manner of speaking, David intended to show that the territory of Judea was too narrow to contain the infinite greatness of Jehovah’s praises.” Our God is worthy of being proclaimed among the hostile and unfavorable peoples.
This should not be considered a rebuke of those who labor among people where God’s name has already been claimed. Those called to labor among people already exposed to the gospel are true servants of the Lord. This verse acknowledges the added difficulty of proclaiming the gospel to hostile or unfamiliar people groups. Those who have been called to pronounce the truth to previously unaware people are faced with additional anxiety, and a steeper learning curve. The fulltime ministers of the gospel who proclaim to new lands are no more obedient or holy than other missionaries. However, their sacrifices and labors warrant special prayer and support.
 John Calvin and James Anderson, Commentary on the Book of Psalms, vol. 1 (Bellingham, WA: Logos Bible Software, 2010), 120–121.