وَلَا تَقُولَنَّ لِشَاْيۡءٍ إِنِّي فَاعِلٞ ذَٰلِكَ غَدًا

Wa laa taqoolanna lishai'in innee faa'ilun zaalika ghadaa

Nor say of anything, "I shall be sure to do so and so tomorrow"-

— Al-Kahf (ٱلْكَهْف), 18:23