Why: acts of sacrifice, charity, and austerity should not be abandoned, but should indeed be performed, for these purify the wise, delivering the actual conclusion, that these specific practices remain valuable and shouldn't be discarded.

In life: some foundational practices genuinely remain valuable throughout a person's growth, rather than being things you eventually graduate beyond and discard entirely as you become more advanced.

Teaching: identify a foundational practice in your own life that you might have been tempted to discard as you've grown more experienced, and reconsider whether it might still be genuinely purifying and worth continuing rather than something to graduate past.