Why: not by the Vedas, austerity, charity, or sacrifice can I be seen in the form you have seen me, again reinforcing the vision's rarity, this time by explicitly ruling out the standard, expected methods of religious effort as sufficient causes for it.

In life: some of your most significant experiences didn't arrive through the methods you'd normally expect to produce significant experience, and that's worth noticing rather than assuming there's always a direct, reliable method for every meaningful thing that happens to you.

Teaching: notice when a significant experience of yours didn't arrive through any of the methods you'd normally expect, and let that observation loosen any assumption that meaningful experience always follows a predictable, controllable formula.