Psalm of humility and trust.

v1: Contrast Acts 17.21; 1 Tim 1.7; see 1 Sam 17.28; we are to cherish the simple, pure truths of Scripture.

Avoid things that are too profound; beware the pursuit of knowledge for its own sake, for knowledge puffs up. Bible truths are essentially practical. But we should beware of seeking more knowledge merely for the sake of speculation.

'The very same case is this: if thou gaze and stare after every opinion and way that comes into the world; also if thou be prying overmuch into God's secret decrees, or let thy heart too much entertain questions about some nice foolish curiosities, thou mayst stumble and fall, as many hundreds in England have done.... Take heed therefore, follow not that proud and lofty spirit, that, devil-like, cannot be content with his own station.' (John Bunyan, The Heavenly Footman) 

v2: Simple trust in God, the essential mark of true godliness. Like a young child, weaned, happy, satisfied with its mother.

v3: Israel can therefore hope in the Lord always.