Psalm 90 speaks of time, permanence and impermanence, and the span of human life. It upholds the eternal nature of the Lord: "Even from everlasting to everlasting, You are God."

A secondary but connected theme, especially from verses 7-12, is the Lord's apparent anger with us, and his affliction of our lives with troubles. The reason given for this is that we can then learn the true nature of our lives and of our dependence on Him.

The psalm ends with a prayer for the Lord's compassion on us, and for us to be glad all our days, according to the days of our affliction. We wish to know the work of the Lord. We hope that the work of our hands — our purpose and use — will be established.

This is a relatively profound psalm, covering many questions we have about life. It links our sense of our own frailty with the Lord's greater purposes. In the same way that 'time' is basically only an appearance to us, so our unthinking view of life is generally illusory. It can bring us to think of God as angry, and against us. But, nothing could be further from the truth. (See Heaven and Hell 165)

It's important to see that the first two verses are unambiguously true: First, "Lord, You have been our dwelling place in all generations", and second, "even from everlasting to everlasting, You are God". Spiritually, for us, holding this opening statement in our minds allows us to explore our whole relationship with the Lord. (See Arcana Caelestia 3913)

The next four verses bring out the frailty of our existence, that in a sense we are made from the dust of the earth. Spiritually, this is not said to condemn us, but to remind us that without the Lord, we are nothing. (See Arcana Caelestia 8995)

This humility allows us to come into spiritually positive territory. This is brought out in the context of time being as nothing - "a thousand years in God's sight are like yesterday" - they are carried away and temporary. (See Divine Providence 218-219)

From verse 7 onward come descriptions of the Lord's anger and wrath, along with the brevity and futility of our days in life. "We finish our years like a sigh." All of this is said in the language of appearance — of how it can seem to us — when we consider life only from our viewpoint and not from the Lord's purpose in it. (See Arcana Caelestia 1093 and Sacred Scripture 94.) In reality, the Lord does not ever have or hold anger and wrath.

Verse 12 provides a helpful clue to the verses which come before it. It is a prayer from us to the Lord to teach us to number our days, that we may gain a heart of wisdom. This is a lesson learned from our experience in life, with its pitfalls and its speedy passing, when we realise our folly too late.

The last five verses are clearer and brighter, asking the Lord to gladden us in our lives, and for us to see the work of God in all that we go through, and finally for the Lord our God to establish the work of our hands. Note that this positive ending comes from having endured confusion and negative states which we have now worked through, and that they have gone from us. (See Apocalypse Explained 897.)

95. Many depictions in the literal sense are apparent truths that contain genuine truths concealed within them, and it is not harmful to think and speak in accordance with those apparent truths. However, it is harmful to affirm them to the point of destroying the genuine truth that lies concealed within. This, too, may be illustrated by an example found in nature, which I cite because something natural is more clearly instructive and convincing than something spiritual.

[2] To our eyes it appears that every day the sun travels around the earth, and does so also once annually. For that reason it says in the Word that the sun rises and sets, that it causes morning, afternoon, evening and night, as well as the seasons of spring, summer, fall and winter, and thus days and years, even though the sun is stationary. For it is a sea of fire, and the earth revolves daily and travels about it annually.

A person who thinks in simplicity and ignorance that the sun travels around does not destroy the natural truth, namely, that the earth rotates daily about its axis and moves along its orbit annually.

On the other hand, someone who affirms as true the apparent motion of the sun and its course because of what it says in the Word, and does so with arguments originating from his natural self, weakens the truth, and also destroys it.

[3] The idea that the sun moves is an apparent truth. The fact that it does not move is a genuine truth. Everyone may speak in accordance with the apparent truth, and also does speak so, but to think accordingly with conviction dulls the rational intellect and darkens it.

The case is the same with the stars in the sky. It is an apparent truth that they also travel about once daily, like the sun, which is why it is also said of the stars that they rise and set. But the genuine truth is that the stars are fixed, and the sky in which they appear is stationary. Still, everyone may speak in accordance with the appearance.