Lawmage's Binding

• WOTC Official Reminder Textofficial rules
  Flash — You may cast this spell any time you could cast an instant.

• WWizards of the Coast2019-01-25
  Official Ruling
  Activated abilities contain a colon. They’re generally written “[Cost]: [Effect].” Some keyword abilities are activated abilities and will have colons in their reminder text. Triggered abilities (starting with “when,” “whenever,” or “at”) are unaffected by Lawmage’s Binding.
• WWizards of the Coast2019-01-25
  Official Ruling
  Once a creature has attacked or blocked, casting Lawmage’s Binding won’t remove that creature from combat. Similarly, once a creature’s ability has been activated, casting Lawmage’s Binding won’t counter that ability.

Rulings via Scryfall