أَشِدَّاءُ عَلَى الْكُفَّارِ رُحَمَاءُ بَيْنَهُمْ
Firm toward the disbelievers and merciful among themselves.
This sort of example raises the question whether indirectly related oppositions should count as ṭibāq or be treated as associated figures. Severity and mercy acquire a contrast through mercy’s relationship to gentleness rather than through a perfect lexical antonym pair.
The lesson is to state the exact reason for the contrast. Merely naming two different words does not establish either figure.