The phrases are from Psalm 35 as found in the Book of Common Prayer.
"and my soul shall be joyful in the Lord;
it shall rejoice in his salvation.
All my bones shall say, Lord
who is like unto thee...?"
It is as though David in this 'song of struggles' cannot be content with just saying the words. His experiences with his God go wide and deep. So must the expression of his heart. The depth of his feelings and his praise seem even to have penetrated his very bones. Even his bones declare the reality and truth of his devotion.
"O deliver my soul from the calamities
which they [mine adversaries] bring on me,
and my darling from the lions."
Just as in truth God collects our tears in His bottle and records our griefs, so our Adversary keeps record of all our sins and wrong doings. These he uses to remind us of our spiritual treason. These he rehearses before the Throne. And in Grace, the One on that Throne reminds him of our status by both promise and right of purchase.
But it is the term "my darling" the is the sweet part of this verse. What an interesting choice of words! My darling is my soul - my one and only, my solitary one. The secret, private inner me that feels desolate, deserted, hopeless. But here is the reminder that regardless of the accusations and roarings of that lion, the enemy of our souls, our 'darling' is also God's dear one and so will find rescue and be safe.
"And as for my tongue,
it shall be talking of thy righteousness,
and of thy praise,
all the day long."
Our life is not to be only a tedium of repetitions, of words. Words are important, but as Augustine reminds us if we sing, we praise. Whatever is done well is praise. When we do not do evil, that too is praise. To do no wrong when transacting business is praise. Now quoting Augustine directly:
"Dost thou till thy field? Then do not [fret], thou has praised God.
In the innocency of thy works prepare thyself to praise God all the day long."
So Dear Reader and fellow pilgrim, let us 'till today's field' in faithfulness and with rejoicing.