At that time the flowering of bamboo was considered a bad omen, portending natural or man-made disasters, and since even mentioning such an event could cause it to happen, doing so could cost a person his life.
這是因為古人視竹子開花為不祥之兆，「竹泯」（竹因開花而泯滅）被認為是天災人禍之始，隨口招忌，是要砍頭的。