Owen on Zephaniah 3:17

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 his love, he will joy over thee with singing.

(Zephaniah 3:17 KJV).

God joys over us. According to Owen, the word means an outward expression of joy such as leaping. God is so happy that he is singing over us.

Here is the quote from Chapter 3 in Communion of God by John Owen.

(1st.) The love of God is so. Zeph. 3: 17, "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 his love; he will
joy over thee with singing." Both these things are here
assigned unto God in his love, - REST and DELIGHT. The words
are, "yacharish be'ahavato" - "He shall be silent because of
his love." To rest with contentment is expressed by being
silent; that is, without repining, without complaint. This God
does upon the account of his own love, so full, so every way
complete and absolute, that it will not allow him to complain
of any thing in them whom he loves, but he is silent on the
account thereof Or, "Rest in his love;" that is, he will not
remove it, - he will not seek farther for another object. It
shall make its abode upon the soul where it is once fixed, for
ever. And COMPLACENCY or DELIGHT: "He rejoiceth with singing;"
as one that is fully satisfied in that object he has fixed his
love on. Here are two words used to express the delight and
joy that God has in his love, - "yasis" and "yagil". The first
denotes the inward affection of the mind, joy of heart; and to
set out the intenseness hereof, it is said he shall do it
"besimchah", - in gladness, or with joy. To have joy of heart
in gladness, is the highest expression of delight in love. The
latter word denotes not the inward affection, but the outwards
demonstration of it: "agalliain" seems to be formed of it. It
is to exult in outward demonstration of internal delight and
joy; - " Tripudiare," to leap, as men overcome with some
joyful surprisal. And therefore God is said to do this
"berinnah" - with a joyful sound, or singing. To rejoice with
gladness of heart, to exult with singing and praise, argues
the greatest delight and complacency.