Scale them fishes, my love is concrete
When you scale a fish you cut it.
Kim is referring to her fellow side chicks as fish, and telling BIG to go ahead and fuck (cut) them, because she knows (or thinks) that Biggie knows how solid her love for him is and feels the same way about her.
To help improve the meaning of these lyrics, visit “Another” by The Notorious B.I.G. (Ft. Lil Kim) Lyrics and leave a comment on the lyrics box