Let Israel hope in the Lord ... - The connection would seem to require us to understand this as the assertion of him who had been accused of thoughts which seemed to be too lofty. As the result of all his reflections (of those reflections for which he was rebuked and charged with pride, but which were really conceived in a modest spirit) - as expressing what he saw that seemed to be in advance of what others saw, or to indicate a habit of thought beyond his years - he says that there were reasons why Israel should hope in the Lord; that there was a foundation for confident trust; that there was that in the divine character which was a just ground of reliance; that there was that in the course of events - in the tendencies of things - which made it proper for the people of God, for the church, to hope, to confide, to feel assured of its ultimate and permanent safety. This would indicate the nature of the suggestions which he had expressed, and which had exposed him to the charge of arrogance; and it would also indicate a ripe and mature habit of thinking, beyond what might be expected from one in very early life. All this was, probably, applicable to David in his early years, as to the reflections which might have foreshadowed what he would be in future; this was eminently applicable to David's Descendant - greater than he - who, at twelve years of age, astonished the Hebrew doctors in the temple with "his understanding and answers" Luke 2:47; this gives a beautiful view of modesty joined with uncommon gifts in early life; this shows what is always the nature of true religion - as producing modesty, and as prompting to hope.

Psalm 131:3 Parallel Commentaries

That the Ruler Should be Discreet in Keeping Silence, Profitable in Speech.
The ruler should be discreet in keeping silence, profitable in speech; lest he either utter what ought to be suppressed or suppress what he ought to utter. For, as incautious speaking leads into error, so indiscreet silence leaves in error those who might have been instructed. For often improvident rulers, fearing to lose human favour, shrink timidly from speaking freely the things that are right; and, according to the voice of the Truth (Joh. x. 12), serve unto the custody of the flock by no means …
Leo the Great—Writings of Leo the Great