Monk of the Open Hand — ruling 1

Monk of the Open Hand doesn't need to have been on the battlefield as the first spell was cast. For example, if Monk of the Open Hand is the first spell you cast, and then you cast another spell after the Monk resolved, that spell would cause the Flurry of Blows ability to trigger.

Monk of the Open Hand — ruling 2

If Monk of the Open Hand is the second spell you cast in a turn, spells you cast after that point in the same turn will not cause the Flurry of Blows ability to trigger.

Monk of the Open Hand : règles, fonctionnement et interactions (MTG)

Monk of the Open Hand 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

Flurry of Blows — Whenever you cast your second spell each turn, put a +1/+1 counter on this creature.

How it works : Monk of the Open Hand

Original English text — Wizards of the Coast / Scryfall

#1July 23, 2021· Wizards of the Coast
Monk of the Open Hand doesn't need to have been on the battlefield as the first spell was cast. For example, if Monk of the Open Hand is the first spell you cast, and then you cast another spell after the Monk resolved, that spell would cause the Flurry of Blows ability to trigger.
No other card is named in this ruling.
#2July 23, 2021· Wizards of the Coast
If Monk of the Open Hand is the second spell you cast in a turn, spells you cast after that point in the same turn will not cause the Flurry of Blows ability to trigger.
No other card is named in this ruling.

Interactions with other cards

These cards' text mentions Monk of the Open Hand.

Grand Master of Flowers

As long as Grand Master of Flowers has seven or more loyalty counters on him, he's a 7/7 Dragon God creature with flying and indestructible. +1: Target creature without first strike, double strike, or vigilance can't attack or block until your next turn. +1: Search your library and/or graveyard for a card named Monk of the Open Hand, reveal it, and put it into your hand. If you search your library this way, shuffle.