Psalm 71 is a noble psalm with no stated author (although verses 1 to 3 are very similar to part of psalm 31, a psalm of David). It has the themes of giving our trust to the Lord at all times, and of the passage through our life, from birth through to being elderly and grey-haired. The Lord is described as our rock and our fortress.

It brings out the well-founded truth that in old age, having lived for many years and having gone through all kinds of different experiences, there is often a coming into wisdom which is not present in earlier life.

This is also a psalm expressing the certainty of being able to depend on the Lord, that when we turn to Him to bring us back from whatever false or apparent thoughts, fears, and sensations we're having. Words and phrases such as ‘never’, ‘continually’, ‘all the day’, ‘on every side’ ring through the psalm. (Arcana Caelestia 8066-8067)

The speaker is keenly aware of his adversaries, yet he declares ‘I have become a wonder to many’. This ‘wonder’ could be due to the sheer number of attacks on him, or to his resilience when attacked. It gives us some sense of the inner state of Jesus during his life in the world, too, where no one would have been able to know his full state but could only marvel. He saw all his states portrayed throughout the psalms. (Arcana Caelestia 1690)

The psalm begins with an acknowledgement of the Lord’s power to bring us from dark into light, from fear into security and strength. The words, “You have given the commandment to save me” are not an absolute decree of our salvation, because that would transgress our spiritual freedom. It is the divine promise of salvation when we will it and act to receive it. (Divine Providence 325)

This theme continues, declaring the experience of deliverance, hope, trust and being upheld by God. This is from ‘birth’ and ‘from out of my mother’s womb’. These physical images stand for the first states of our regeneration of our spiritual birth, and being born and delivered from our first natural states of our proprium and selfhood. (Arcana Caelestia 4918.2)

Next comes the idea of our “old age”. This is linked with the onslaught of evil which, on seeing frailty, seeks to undermine and destroy. “Old age”, understood spiritually, means the end of a previous state and the start of a new state, a further period in our regeneration. (Arcana Caelestia 3492) The references to enemies, adversaries and ‘those who lie in wait for my life’ stand for the experience of temptation – especially the Lord in his temptation – that we have no power to withstand on our own, but are frail.

Verses 12 to 16 are a series of short, sharp affirmations of certainty of the Lord’s help and our hope. Spiritual hope is to put ourselves fully in the Lord’s providence and care while we yet determine to live according to his commands. It is not a resignation, but a firming up. (Arcana Caelestia 3913)

Then we come back to the idea of our youth and our old age being the remembrance of the Lord’s guidance and leading all through our life. And, as before, we have the prayer to be upheld so that the coming generations – which are our future states – will come to be from our present love and faith in the Lord. (True Christian Religion 584)

From verse 19 to the end there is a eulogy of praise to the Lord, first for what He has done and always will do for us, and then our response, pictured by playing the lute and the harp, and by singing and speaking all the day long. Stringed musical instruments stand for our acknowledgement of and affection for spiritual truths, while singing and speaking refer more to our desire to live these truths. (Apocalypse Explained 323)