If you cannot download this mod from Nexus, (a weird Nexus bug, which happened with this mod already once) please visit my website and download it from the Dropbox link that I provided.

In vanilla, the Mages' Guild and the Fighters' Guild have a supply chest. My Imperial Legion Expansion mod adds one for the Imperial Legion, and after a brief, three minute research, I could determine that two mods made by others exist, one adds a supply chest of the Thieves' Guild and one to the Blades. I thought that I would address the elephant in the room, and add one for the Tribunal Temple too.

The contents of the supply chest:

An apprentice's mortal and pestle
Two potions to cure blight disease
Two potions to cure common disease
One or two random Temple books (Possible ones: The Book of Dawn and Dusk, The Cantatas of Vivec, The Consolations of Prayer, The Doors of the Spirit, Homilies of Blessed Almalexia, The House of Troubles, Lives of the Saints, The Pilgrim's Path, Saryoni's Sermons)
Two scrolls of Almsivi Intervention
A Temple/Indoril Robe
An Ancestor's Ring (Summon Ancestral Ghost for 60 secs)

Locations of the supply chest, and how to acquire its contents:

For the sake of balance, and being immersive, possibly to be as compatible with other mods as possible, there are only two chests: One in the Balmora Temple (upstairs) and one in the Ald-ruhn Temple (near the entrance). A supply chest could have been added to each Temple, but it would have hurt the balance of the game, and also while technically it's possible to join up even at Ghostgate, or Molag Mar, one who roleplays the game wouldn't really have a reason to go and join up there, they would likely join up either in Balmora or Ald-ruhn.

Because I like messing with you, you also need to be at least a Novice in the Temple (complete at least the first quest) to take the stuff legally. No free loot just for clicking at one topic in the dialogue. :)

The two supply chests, like every supply chest in the game, respawn after a couple of in-game months, though.

Compatibility:

Should be compatible with any mod, unless that mod adds something to that exact location inside the cells where I have placed the chests.

The mod should be bug-free and clean too.