What is the main grammatical question concerning “wa-l-rāsikhūn fī al-ʿilm” in 3:7?

Muḥkam, Mutashābih, Kināyah, Taʿrīḍ and Figurative Attribution

• Changing plural to dual
• Whether wāw coordinates or starts a new clause
• A difference in verbal stem
• A question about definiteness