So don't eye 'em they get the wrong message, wrong methods
Put you on that long stretcher
He is saying if you look at someone the wrong way, they get the wrong message and would most likely hurt you, hence being on the long stretcher.
Some clever wordplay here as “eye ‘em” is a homophone of “I.M.” which stands for instant message. This relates to “get the wrong message.” .
To help improve the meaning of these lyrics, visit "Hardknock" by Joey BADA$$ (Ft. CJ Fly) Lyrics and leave a comment on the lyrics box