53 cards where the card is available on Paper and it’s legal in Commander and the color identity ≤ BW and the text includes “discard a card:” and the mana value < 4

Avenger en-Dal (Nemesis #2)
Bog Witch (Archenemy #11)
Cabal Initiate (Modern Horizons 2 #78)
Cackling Witch (Mercadian Masques #119)
Call the Bloodline (Shadows over Innistrad #103)
Charm Peddler (Mercadian Masques #6)
Chivalric Alliance (March of the Machine Commander #11)
Cho-Arrim Alchemist (Mercadian Masques #8)
Cryptbreaker (Eldritch Moon #86)
Devout Witness (Mercadian Masques #17)
Divining Witch (Nemesis #57)
Fledgling Imp (Odyssey #137)
Fleeting Spirit (Innistrad: Crimson Vow #14)
Fodder Tosser (Modern Horizons 2 #226)
Fomori Vault (The Big Score #29)
Guardian of New Benalia (Dominaria United #19)
Heirloom Mirror // Inherited Fiend (Innistrad: Midnight Hunt #105)
Heirloom Mirror // Inherited Fiend (Innistrad: Midnight Hunt #105)
Heir of Falkenrath // Heir to the Night (Shadows over Innistrad #116)
Heir of Falkenrath // Heir to the Night (Shadows over Innistrad #116)
Hypochondria (Torment #7)
Icatian Crier (Ultimate Masters #22)
Instigator (Mercadian Masques #140)
Key to the City (Commander 2021 #248)
Medicine Bag (Exodus #133)
Merciless Eternal (Hour of Devastation #71)
Mortiphobia (Torment #72)
Netter en-Dal (Nemesis #13)
Oblivion Crown (Future Sight #73)
Olivia's Dragoon (Ultimate Masters #109)
Oona's Prowler (Double Masters 2022 #85)
Pack Rat (Return to Ravnica #73)
Patchwork Gnomes (Modern Horizons 2 #299)
Patrol Hound (Odyssey #38)
Peace of Mind (Eldritch Moon #36)
Plague Witch (Eternal Masters #103)
Putrid Imp (Torment #77)
Ridged Kusite (Time Spiral Remastered #134)
Seasoned Hallowblade (Core Set 2021 #34)
Skirk Ridge Exhumer (Future Sight #77)
Skirsdag Supplicant (Eldritch Moon #104)
Sliversmith (Time Spiral Remastered #273)
Stern Constable (Shadows over Innistrad #39)
Stromkirk Condemned (Crimson Vow Commander #137)
The Underworld Cookbook (Modern Horizons 2 #240)
Thraben Standard Bearer (Eldritch Moon #48)
Tireless Tribe (Odyssey #56)
Tomb Robber (Rivals of Ixalan #87)
Tonic Peddler (Mercadian Masques #54)
Toymaker (Mercadian Masques #314)
Trained Pronghorn (Judgment #30)
Trespasser il-Vec (Time Spiral Remastered #147)
Undead Gladiator (Dominaria Remastered #105)
Undertaker (Time Spiral Timeshifted #53)
Urborg Syphon-Mage (Dominaria Remastered #106)

It is the moment of discovery, the triumph of the mind, and the end of these results.