Yaknufānihā is a dual masculine imperfect verb, with -hā as its object pronoun. Its dual ending indicates two flanking structures. Kināsay is dual accusative after kaʾanna.
In ṣulbin muʾayyadin, ṣulb is genitive, and muʾayyad is its agreeing adjective. Muʾayyad is a passive participle meaning strengthened or supported, an important link to the earlier masonry imagery.