Study meaning: Did He not cause their scheme to fail?
The scheme was made to fail. Kaydahum means their plan or plotting. Learn the link between the two opening questions: alam tara, then alam yaj‘al. The emphasis is Allah’s power over the attack, not the number or equipment of the army.
Return to ayahs 1-1, then add this ayah. If a phrase is difficult, practise less material and return later. A parent can listen and encourage without asking the learner to compete.
Read the Quran passage and Ibn Kathir commentary. Study meanings are simplified; the commentary provides the wider explanation.