Narrated Ibn Mas'ud (RA):

Allah's Messenger (ﷺ) said: "Do not buy the fish that is in the water, for it involves uncertainty (risk)." [Reported by Ahmad who indicated that the correct view is that it is Mawquf (saying of a Companion, i.e. Ibn Mas'ud].

وَعَنِ اِبْنِ مَسْعُودٍ ‏- رضى الله عنه ‏- قَالَ: قَالَ رَسُولُ اَللَّهِ ‏- صلى الله عليه وسلم ‏-{ لَا تَشْتَرُوا اَلسَّمَكَ فِي اَلْمَاءِ; فَإِنَّهُ غَرَرٌ } رَوَاهُ أَحْمَدُ, وَأَشَارَ إِلَى أَنَّ اَلصَّوَابَ وَقْفُهُ [1]‏ .‏