The LORD thy God in the midst of thee is mighty; he will save, he will rejoice over thee with joy; he will rest in {n} his love, he will joy over thee with singing.

(n) Signifying, that God delights to show his love and great affection toward his Church.

King James Translators' Notes

rest: Heb. be silent

Jamieson-Fausset-Brown Bible Commentary

17. he will rest in his love-content with it as His supreme delight (compare Lu 15:7, 10) [Calvin], (Isa 62:5; 65:19). Or, He shall be silent, namely as to thy faults, not imputing them to thee [Maurer] (Ps 32:2; Eze 33:16). I prefer explaining it of that calm silent joy in the possession of the object of one's love, too great for words to express: just as God after the six days of creation rested with silent satisfaction in His work, for "behold it was very good" (Ge 1:31; 2:2). So the parallel clause by contrast expresses the joy, not kept silent as this, but uttered in "singing."

Matthew Henry's Concise Commentary

3:14-20 After the promises of taking away sin, follow promises of taking away trouble. When the cause is removed, the effect will cease. What makes a people holy, will make them happy. The precious promises made to the purified people, were to have full accomplishment in the gospel. These verses appear chiefly to relate to the future conversion and restoration of Israel, and the glorious times which are to follow. They show the abundant peace, comfort, and prosperity of the church, in the happy times yet to come. He will save; he will be Jesus; he will answer the name, for he will save his people from their sins. Before the glorious times foretold, believers would be sorrowful, and objects of reproach. But the Lord will save the weakest believer, and cause true Christians to be greatly honoured where they had been treated with contempt. One act of mercy and grace shall serve, both to gather Israel out of their dispersions and to lead them to their own land. Then will God's Israel be made a name and a praise to eternity. The events alone can fully answer the language of this prophecy. Many are the troubles of the righteous, but they may rejoice in God's love. Surely our hearts should honour the Lord, and rejoice in him, when we hear such words of condescension and grace. If now kept from his ordinances, it is our trial and grief; but in due time we shall be gathered into his temple above. The glory and happiness of the believer will be perfect, unchangeable, and eternal, when he is freed from earthly sorrows, and brought to heavenly bliss.