"And never say of anything, Surely, I will do that tomorrow except when adding InshaAllah" Al-Qur'an - القرآن 18:23-24
"Perhaps you hate a thing and it is good for you; and perhaps you love a thing and it is bad for you. And Allah Knows, while you know not." -- Surah Al-Baqarah [2:216]
Prophet Muhammad (PBUH) said: “The first matter that the slave will be brought to account for on the Day of Judgement is the prayer. If it is sound, then the rest of his deeds will be sound. And if it is bad, then the rest of his deeds will be bad."