NET
8 I am not saying this as a command, but I am testing the genuineness of your love by comparison with the eagerness of others.
Darby
8 I do not speak as commanding [it], but through the zeal of others, and proving the genuineness of your love.
KJV
8 I speak not by commandment, but by occasion of the forwardness of others, and to prove the sincerity of your love.