增壹阿含經 24.5.p2

24.5.p2

It was then that the Bhagavān had this thought, “Now, I have attained this profound teaching that’s hard to understand, hard to comprehend, hard to realize, and hard to know. It’s an extremely subtle and sublime knowledge that I’ve realized and known. Now, to whom will I explain this teaching first? Who’ll understand this teaching of mine?”