Psalm 71 explains how God is our refuge in older years, giving continual hope and strength.
It is reasonable to think the author of Psalm 71 made study and meditation upon God’s word a priority through his life, and the result is that he naturally used the phrases and vocabulary of the Scriptures to pray and praise.

Here is a link to David Guzik's commentary on Psalm 71: https://enduringword.com/bible-commen...