The last giving in Dana Mahapphala Sutta

Dana Sutta:

" — but with the thought, 'This is an ornament for the mind, a support for the mind' — on the break-up of the body, after death, he reappears in the company of Brahma's Retinue. Then, having exhausted that action, that power, that status, that sovereignty, he is a non-returner. He does not come back to this world.

At the end of sutta, said that the last dāna-method, your quote, is dāna of anāgāmi-ariya:

with the body’s breaking up, after death, he reappears in the company of Brahma’s Retinue. Then, having exhausted that karma, that power, that status, that sovereignty, he is a non-returner. He does not come back to this world.

So, in this sutta's commentary said:

"an adornment for the mind, a support for the mind" means a support for concentration-meditation-mind and insight-meditation-mind.

Because, anāgāmi-ariya completely & perfectly escaped five strands of sensuality, kāma-attachment, so his attachment in his gift can't arise anymore, too, because gift is five strands. So, dāna in the last method are the best, because it is giving as alike as anāgāmi-ariya's and arahanta-ariya's giving. These two ariya just give for meditation, mind development.

To understand tipitaka deeply, reciting & memorizing tipitaka are strongly required.