ما الفرق بين "لا سمح الله" و "لا قدر الله"؟

The difference between "al-samh" (permission) and "al-taqdir" (ordainment/determination) in the Arabic language is that "al-samh" means to permit something, while "al-taqdir" means to do something. The meaning of Allah's saying: ﴿فَقَدَّرَهُ تَقْدِيرًا﴾ (So He proportioned it with due proportion) means He created it with precision, perfection, and exactness.

Sheikh Ibn Uthaymeen warned that the phrase "la samah Allah" (may Allah not permit it) should not be uttered because it implies that Allah is compelled to do something. It is more appropriate to say "la qaddara Allah dhalik" (may Allah not ordain that), which is a correct phrase and its meaning is a supplication that Allah may not ordain that thing. In the fatwas of the Permanent Committee, there is no harm in saying "la samah Allah" or "la qaddara Allah" if the intention is to seek well-being.