Exercising caution with regards to the use of the tongue

Recently I had a dream wherein I was at a musjid and my uncle, who is an Aalim, placed a weed/zol in his mouth. He showed everyone this as if it was something good. Thereafter I took it and I placed it in my mouth and some of the crushed weed inside came into my mouth, filling it. I then proceeded towards the door of the musjid. This dream was before awakening for fajr, around tahajjud time. Please interpret it for me.