Vocabulary

They crucified him (ṣalabūh): “Firmness” (ṣalāba) (hardness and solidity) is the opposite of “softness” (līn). Crucifixion is called “ṣalb” because the crucified person is bound so firmly to the cross that he cannot save himself.(2)

Doubt (shakk): “Shakk” means being of two minds. According to the pioneers of lexicography, doubt is the opposite of certainty. Doubt is hesitation between two things; whether the two sides are equal to each other, or one of the two sides has superiority over the other.(3)

Note: Doubt is the opposite of scientific certainty (jazm ʿilmī) and hesitation (tardīd) is the opposite of practical resolve (ʿazm ʿamalī), although each is used in relation to the other.