It's some sort of translation of the very last line of the Nicomachean Ethics Book VIII Part 3 1156b25:
οἱ δὲ ταχέως τὰ φιλικὰ πρὸς ἀλλήλους ποιοῦντες βούλονται μὲν φίλοι εἶναι, οὐκ εἰσὶ δέ, εἰ μὴ καὶ φιλητοί, καὶ τοῦτ' ἴσασιν· βούλησις μὲν γὰρ ταχεῖα φιλίας γίνεται, φιλία δ' οὔ.
[W. D. Ross transl.:]
Those who quickly show the marks of friendship to each other wish to be friends, but are not friends unless they both are lovable and know the fact; for a wish for friendship may arise quickly, but friendship does not.
[Alternative transl.:]
However, those who at once offer the services of friendship show that they wish to be friends but in fact are not unless they are lovable to each other and know it. So then the wish for friendship is quickly made but not friendship itself.
[cf. DeepL transl.]