Joined Cases C-451/21 P and C-454/21 P: Judgment of the Court (Grand Chamber) of 5 December 2023 — Grand Duchy of Luxembourg, Engie Global LNG Holding Sàrl, Engie Invest International SA, Engie SA v European Commission, Ireland (Appeal — State aid — Article 107(1) TFEU — Tax rulings adopted by a Member State — Aid declared incompatible with the internal market — Obligation to recover that aid — Concept of ‘advantage’ — Determination of the reference framework — ‘Normal’ taxation under national law — Review by the Court of Justice of the interpretation and application of national law by the General Court of the European Union — Direct taxation — Strict interpretation — Powers of the European Commission — Obligation to state reasons — Legal classification of the facts — Concept of ‘abuse of law’ — Ex ante assessment by the tax authorities of the Member State concerned — Principle of legal certainty)