A phrase used commonly among stoner's when somebody forgets that they are currently in possession of the pipe or joint and proceeds to babble nonsensically prior to taking their hit. The phrase "smoke weed" is used in these situations to remind the offender to take their hit and pass it because others are waiting on them. This phrase is often followed by the word "damn it" or "bitch".
Dave: *passes joint to carl*
Carl: Ya know man, i bet we could turn your neighbors pool into a giant assgravity bong! we just need, like a trash can and some other shit
Next kid in circle: Smoke weed, bitch
Snoop Dogg's most famous line advocating for daily marijuana usage.
It has spawned a huge number of joke variants, many of which somehow involve Super Mario. When the player goes down a pipe, the well-known transit noise is replaced by a squeaky voice saying "weed" three times. Need I say more?
Most implementations of this phrase occur along with a GIF of Snoop Dogg's "weed dance", a classic move which is at once simple in appearance but actually quite difficult to pull off. Perhaps one needs to smoke pot before attempting it...