How to get Shimsil - Elder Scrolls: Morrowind
Video: How to get Shimsil
Shimsil is a unique short sword which is obtained from defeating Delvam Andarys in the Mawia dungeon. You can find Mawia southeast of Molag Mar on an island just off the coast. The dungeon itself is pretty small and straight forward - aside from Delvam Andarys there will be a couple of Skeletons and Liches inside.
In addition to the Shimsil short sword that he drops you can also find a Ring of Regeneration on Delvam. This ring provides you with a slow HoT spell that heals 1 damage every second for 120 seconds, it's actually one of the better Cast on Use items you can get early in the game.
Delvam Andarys is part of the Necromancer in Mawia Side Quest which is given to you by the Tribunal Temple faction. However, the quest does not need to be active for you to come here and find/defeat Delvam. As with most Elder Scrolls games he'll always drop his ring and sword regardless of the quest.