وَمَنَوَانِ سَمْنًا
Translation: And two mann weights of clarified butter.
وَ: conjunction.
مَنَوَانِ: dual quantity term, nominative by alif, coordinated with the earlier subject.
سَمْنًا: accusative tamyīz naming the weighed substance.
The dual provides the quantity; samnan identifies what is weighed.