Surge of Salvation
Instant
You and permanents you control gain hexproof until end of turn. Prevent all damage that black and/or red sources would deal to creatures you control this turn.
No Meletian had ever laid eyes on an angel, but when protective Halo flooded the Multiverse, they knew a divine blessing was at hand.
Dominik Mayer
Rulings
The set of permanents that gain hexproof is determined as Surge of Salvation resolves. Permanents you begin to control later in the turn won't gain hexproof. However, the damage prevention effect will apply to all creatures you control throughout the turn, even if you didn't control them (or they weren't creatures) as Surge of Salvation resolved.
(wotc • 2023-04-14)
Rulings
The set of permanents that gain hexproof is determined as Surge of Salvation resolves. Permanents you begin to control later in the turn won't gain hexproof. However, the damage prevention effect will apply to all creatures you control throughout the turn, even if you didn't control them (or they weren't creatures) as Surge of Salvation resolved.
(wotc • 2023-04-14)