Umar ibn al-Khattab, May Allah be pleased with him said ,”The best acts are doing what Allah has commanded, staying far from what Allah has forbidden, and having sincere intentions towards whatever Allah has required of us”. Some of our Predecessors said, “Many small actions are made great by the intentions behind them. Many great actions, on the other hand, are made small because of the intentions behind them are lacking”
Yahya Ibn Abu Kathir said”Learn about intentions, for their importance is greater than the importance of actions “.
Ibn Umar once heard a man who was putting on his Ihram say “O Allah! I intend to do Hajj and Umrah “. So he said to him. “Is it not in fact the people whom you are informing of your intentions? Does not Allah already know what is in your heart? “It is because good intentions are exclusively by the concern of the heart, that they should not be voiced during worship.

—The Purification of the Soul p. 11