41 cards where the card types include “instant” and the text includes “indestructible” and the text includes “gain” and it’s legal in Historic

A-Blessed Hippogriff // A-Tyr's Blessing (Alchemy Horizons: Baldur's Gate #A-85)
Adamant Will (Innistrad: Crimson Vow #1)
Armor of Shadows (Commander Legends: Battle for Baldur's Gate #112)
Assure // Assemble (Ravnica Remastered #248)
Battle-Rage Blessing (Dominaria United #80)
Built to Last (Kaladesh #7)
Chance for Glory (Guilds of Ravnica #159)
Collective Resistance (Modern Horizons 3 #147)
Crumb and Get It (Bloomburrow #8)
Dawn's Truce (Bloomburrow #9)
Destined // Lead (Amonkhet #217)
Fight as One (Ikoria: Lair of Behemoths #12)
Final Showdown (Outlaws of Thunder Junction #11)
Flare of Faith (Innistrad: Midnight Hunt #19)
Gaea's Gift (The Brothers' War #182)
Heroic Intervention (Commander Masters #295)
Inspiring Call (The Lost Caverns of Ixalan Commander #244)
Join Shields (Guilds of Ravnica #181)
Karametra's Blessing (Theros Beyond Death #26)
Loran's Escape (The Brothers' War #14)
Lorehold Command (Strixhaven: School of Mages #199)
Make a Stand (Commander Legends #32)
Moment of Valor (Wilds of Eldraine #20)
Oblivion's Hunger (Zendikar Rising #119)
Offer Immortality (Phyrexia: All Will Be One #102)
Orcish Medicine (The Lord of the Rings: Tales of Middle-earth #104)
Overprotect (Bloomburrow #185)
Professor's Warning (Strixhaven: School of Mages #84)
Resistance Reunited (Phyrexia: All Will Be One #31)
Revitalizing Repast // Old-Growth Grove (Modern Horizons 3 #256)
Revitalizing Repast // Old-Growth Grove (Modern Horizons 3 #256)
Rush of Vitality (Kaladesh #99)
Scales of Shale (Bloomburrow #110)
Sheltering Light (Ixalan #35)
Smuggler's Surprise (Outlaws of Thunder Junction #180)
Take Up the Shield (Outlaws of Thunder Junction #34)
Tamiyo's Safekeeping (Kamigawa: Neon Dynasty #211)
Tyvar's Stand (Phyrexia: All Will Be One #190)
Unbreakable Formation (Ravnica Remastered #32)
Unlikely Aid (Ikoria: Lair of Behemoths #103)
Valorous Stance (Outlaws of Thunder Junction Commander #88)
Yuan-Ti Scaleshield (Alchemy Horizons: Baldur's Gate #71)

Though this query has ended, its relics still slumber in New Argive.