Torah Temimah cites Sanhedrin 30b.
And here they disagree about comparing the telling to the seeing. One master holds we compare telling to seeing; the other holds we do not.
The dispute turns on whether the verse’s linkage of “saw” and “tell” requires that the act of telling match the act of seeing in the same joint fashion. The hekesh (or its refusal) determines the scope of formal testimony under the verse.