"In the tradition of Moses, Miriam, and Deborah, Judith leads the children of Israel in praise and worship of God through a “new psalm".”

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Judith’s Psalm

Prayer is an integral part of the story of Judith just as we discovered of Tobit [7]. In the tradition of Moses, Miriam, and Deborah, Judith leads the children of Israel in praise and worship of God through a “new psalm.” What else can be done when God has delivered us and through the most unexpected means, but praise him. Judith continues the long line of piety in the Hebrew Bible especially in the Psalter. As with other biblical literature there is the rich use of previous biblical literature to nourish the Spiritual well being of God’s people in a new day and situation.

“And Judith said,
Begin a song to my God with tambourines,
and sing to my Lord with cymbals.
Raise to him a new psalm;
exalt him, and call upon his name.
For the Lord is a God who crushes wars;
he sets up his camp among his people;
he delivered me from the hands of
my pursuers.
(Judith 16. 1-2b)

Judith, like the Prophet Miriam (Ex 15.20) and the young ladies in procession in the temple (Ps 68.25) grabs a tambourine and assumes the role of worship leader. In the Bible, God’s fresh act of grace demanded fresh praise. We do not just sing the old song but now in light of God’s new act we sing our own song of worship and praise.
The call to a psalm of praise is grounded in what God has done and is doing. God “crushes” war. Those drunk on the liquor of combat will be disappointed because the Lord simply will put an end to all war. The vision or dream of the prayer is for a world without any more Holoferneses. What a day that would be.
But not only does Judith call to praise because God destroys war but because “he sets up his camp among his people.” Following the destruction of God’s enemies (i.e. war, etc) Judith praises God for one of the great blessings attested to throughout the Hebrew Bible, God lives with his people. It is a vivid image that God “camps” with us. God himself is the desire of the redeemed.
After narrating magnitude of Israel’s dire straits from the Assyrian threat in verses 3 and 4, Judith gives God glory for the unbelievable way in which salvation was granted. Only God could have accomplished salvation through a woman!

“But the Lord Almighty has foiled them
by the hand of a woman.
For their mighty one did not fall by the
hands of the young men,
nor did the sons of the Titans strike
him down,
nor did tall giants set upon him;
but Judith daughter of Merari
with the beauty of her countenance
undid him.” (vv. 5-6)

The Lord God is given total credit for the unusual means of deliverance from the tyrannical Assyrians. Judith does not even give God’s enemy, Holofernes, the honor of being named he is just the “mighty one” who suffers the unbelievable (in that culture) of being done in by a woman, a widow no less! The irony drips form this portion of the psalm. God did not use the demi-gods known as the “sons of the Titans,” nor the legendary “giants” of the land. God used a weapon fit for the occasion that undid the arrogance of an insatiable oppressor. .... Should God not be praised?

Judith continues to narrate in the psalm how the God inspired actions of a widow had cosmic consequences. The Persians and the Medes “tremble” with the news of what God has accomplished through one regarded so helpless (v.10). Kicking into high gear Judith continues her “new song” of praise to the Lord.

“I will sing to my god a new song;
O Lord, you are great and glorious,
wonderful in strength, invincible.
Let all your creatures serve you,
for you spoke and they were made.
You sent forth your Spirit, and it
formed them;
there is none that can resist your
voice.
For the mountains shall be shaken to
their foundations with the waters;
before your glance the rocks shall
melt like wax.
But to those who fear you
you show mercy.
For every sacrifice as a fragrant offering
is a small thing,
and the fat of all whole burnt
offerings to you is a very little thing;
but whoever fears the Lord is great forever.

Woe to the nations that rise up against
my people!
The Lord Almighty will take
vengeance on them in the day of
judgement;
he will send fire and worms into their
flesh;
they shall weep in pain forever.”
(vv. 13-17).

Judith has unwavering faith in the majesty and uniqueness of our God. He is the Creator of all things. Through the instrumentality of the Spirit life is given and the world is made. God’s all powerful word (voice) cannot be resisted by his creation. Those in rebellion against his lordship (like Holofernes) will find themselves missing their head but mercy is the lot of those who walk the dangerous road of faith.

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Taken from: http://stonedcampbelldisciple.com/2013/08/21/prayer-in-the-apocrypha-3-judiths-psalm-of-praise/