How is ʿilma in ʿilma al-yaqīn best understood grammatically?

Supplementary Practice 19: Comparative Rhetorical Analysis of Sūrat al-ʿAṣr and al-Takāthur

• The subject of law
• The predicate of al-yaqīn
• An accusative verbal noun reinforcing taʿlamūn
• A genitive complement of taʿlamūn