What advice does he give to Romeo?

Hey, line numbers are usually not the same with each publication of R&J. Still, I think I know what line the question refers to. The Friar advises Romeo not too be too wild and impulsive with his love for Juliet. That's one of the tragic flaws of these two kids,

"The sweetest honey

Is loathsome in his own deliciousness

And in the taste confounds the appetite.

Therefore love moderately. Long love doth so.

Too swift arrives as tardy as too slow."