The suttas explain that dana offered to a perfectly enlightened Buddha brings greater fruit than a gift to an Arahant, which brings greater fruit than a gift to a Non-Returner and so on down the chain of enlightenment through to the unenlightened wanderers of other sects.
I'm wondering what the explanation for this kammic correlation is? What is it that makes it so?
"Having understood name-and-form, which is a product of prolificity,
And which is the root of all malady within and without,
He is released from bondage to the root of all maladies,
That Such-like-one is truly known as 'the one who has understood'." (Snp 3.6)
"Whether I were to preach in brief, Sāriputta, or whether I were to preach in detail, Sāriputta, or whether I were to preach both in brief or in detail, Sāriputta, rare are those who understand." (A I 333, Sāriputtasutta)