9 cards where the text includes “one spell each turn” and it’s legal in Commander

Arcane Laboratory (Seventh Edition #60)
Archon of Emeria (Zendikar Rising #4)
Colfenor's Plans (Lorwyn #106)
Curse of Exhaustion (Dark Ascension #5)
Eidolon of Rhetoric (Journey into Nyx #10)
High Noon (Outlaws of Thunder Junction #15)
Moderation (Modern Horizons 2 #206)
Rule of Law (Core Set 2020 #35)
Yawgmoth's Agenda (Invasion #135)

The arc of my blade has carved a path of light to the end of these results.