There just might not be any Passuk that starts with Samack and ends with Aleph. I checked with the Orayta app and there was no listing for ?-?.
Yeah, that’s very tough. Samech is one of the rarest letters in the alphabet (only two pesukim in Chumash start with it). Also, not too many verses in Hebrew would end with an aleph (although your best bet might be in Daniel where a good portion of the book is Aramaic and an aleph-ending verse is far more likely).
The Wolf