Hedgewitch's Mask — ruling 1

The blocking restriction is applied only when blockers are declared. Once a creature equipped with Hedgewitch's Mask becomes blocked by a creature with power less than 4, increasing that creature's power won't cause the equipped creature to become unblocked.

Hedgewitch's Mask : règles, fonctionnement et interactions (MTG)

Hedgewitch's Mask is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Equipped creature gets +1/+1. Equipped creature can't be blocked by creatures with power 4 or greater. Equip (: Attach to target creature you control. Equip only as a sorcery.)

How it works : Hedgewitch's Mask

Original English text — Wizards of the Coast / Scryfall

#1September 24, 2021· Wizards of the Coast
The blocking restriction is applied only when blockers are declared. Once a creature equipped with Hedgewitch's Mask becomes blocked by a creature with power less than 4, increasing that creature's power won't cause the equipped creature to become unblocked.
No other card is named in this ruling.