לְאָדָם מַעַרְכֵי-לֵב; וּמֵה’ מַעֲנֵה לָשׁוֹן
“Man may prepare the thoughts of his heart, but the response of the tongue is from Hashem.”
— Mishlei 16:1

A chazan can prepare every note, but when he opens his mouth, it’s Hashem who decides how it sounds.

So too in life: We plan, we speak, but the final word is always His.