COMMENTARY on 4:118
A. Yusuf Ali:

Translation:
Allah did curse him, but he said: "I will take of Your servants a portion 628 Marked off;
Commentary:

628  Satan obtained Allah's permission to tempt man, and this was implied in such free will as was granted to man by Allah. Satan's boast is that the portion of mankind seduced by him will be so corrupted in their nature that they will bear a sort of brand that will mark them off as his own; or that they will be like a portion assigned to himself.