Scriptures “enlarge the memory” in the sense that they remind us of our duty to God and man, of our obligation to cling to goodness and eschew evil. They enlarge the memory to the degree that they bring to remembrance the covenants we have entered into to serve God and keep his commandments. They convince many of the error of their ways as they quicken the spiritual sensitivities and heighten commitment; also, as they hold forth the truth-absolute truth and absolute standards of right and wrong.
This verse reminds us of Paul’s counsel to Timothy: “All scripture given by inspiration of God is profitable for doctrine, for reproof, for correction, for instruction in righteousness: that the man of God may be perfect, thoroughly furnished unto all good works’ (JST, 2 Timothy 3:16-17).”