Charles H. Spurgeon on Psalms 119:90

Thy faithfulness is unto all generations. This is an additional glory: God is not affected by the lapse of ages; he is not only faithful to one man throughout his lifetime, but to his children's children after him, yea, and to all generations so long as they keep his covenant and remember his commandments to do them. The promises are ancient things, yet they are not worn out by centuries of use, for the divine faithfulness endureth for ever. He who succoured his servants thousands of years ago still shows himself strong on the behalf of all them that trust in him. "Thou hast established the earth, and it abideth." Nature is governed by fixed laws; the globe keeps its course by the divine command, and displays no erratic movements: the seasons observe their predestined order, the sea obeys the rule of ebb and flow, and all things else are marshalled in their appointed order. There is an analogy between the word of God and the works of God, and specially in this, that they are both of them constant, fixed, and unchangeable. God's word which established the world is the same as that which he has embodied in the Scriptures; by the word of the Lord were the heavens made, and specially by him who is emphatically THE WORD. When we see the world keeping its place and all its laws abiding the same, we have herein assurance that the Lord will be faithful to his covenant, and will not allow the faith of his people to be put to shame. If the earth abideth the spiritual creation will abide; if God's word suffices to establish the world surely it is enough for the establishment of the individual believer.