49 cards where the text includes “prevent” and the card types include “instant” and the colors is W and it’s legal in Modern

Abuna's Chant (Fifth Dawn #1)
Acolyte's Reward (Born of the Gods #1)
Angelsong (Duel Decks Anthology: Divine vs. Demonic #15)
Awe Strike (Mirrodin #6)
Bandage (Tempest Remastered #7)
Boros Fury-Shield (Ravnica: City of Guilds #5)
Brace for Impact (Dissension #5)
Candles' Glow (Champions of Kamigawa #5)
Channel Harm (Fate Reforged #7)
Chant of Vitu-Ghazi (March of the Machine Commander #177)
Dawn Charm (Commander Legends #371)
Dazzling Reflection (Oath of the Gatewatch #17)
Divine Deflection (Avacyn Restored #18)
Djeru's Resolve (Amonkhet #11)
Eerie Interference (Wilds of Eldraine #12)
Encircling Fissure (Battle for Zendikar #23)
Endure (Eventide #5)
Enshrouding Mist (Magic Origins #13)
Ethereal Haze (Champions of Kamigawa #9)
Festival of the Guildpact (Ravnica: City of Guilds #17)
Forfend (Morningtide #10)
Hallow (Darksteel #4)
Harmless Assault (Rise of the Eldrazi #24)
Healing Grace (Dominaria #20)
Healing Salve (Duel Decks Anthology: Divine vs. Demonic #14)
Hold at Bay (Born of the Gods #18)
Holy Day (Tenth Edition #21)
Honorable Passage (Time Spiral Timeshifted #9)
Inquisitor's Snare (Shadowmoor #8)
Intervention Pact (Future Sight #8)
Leap of Faith (Avacyn Restored #26)
Lithomancer's Focus (Battle for Zendikar #38)
Luminesce (Tenth Edition #28)
Mending Hands (Ninth Edition #29)
Pay No Heed (Duel Decks: Heroes vs. Monsters #19)
Pollen Lullaby (Commander 2011 #26)
Redeem (Eighth Edition #37)
Refraction Trap (Worldwake #17)
Repel the Abominable (Eldritch Moon #38)
Reverse Damage (Ninth Edition #35)
Riot Control (Dragon's Maze #6)
Safe Passage (Magic 2013 #30)
Shielded Passage (Gatecrash #24)
Shieldmate's Blessing (Zendikar #35)
Soul Parry (Duel Decks: Elspeth vs. Kiora #24)
Surge of Salvation (March of the Machine #41)
Swift Maneuver (Coldsnap #21)
Test of Faith (Modern Masters #33)
Withstand (Guildpact #21)

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