Matthew 12:10

χεῖρα ἔχων ξηράν, i.e. paralysed or affected by atrophy. St Luke has ἡ χεὶρ αὐτοῦ ἡ δεξιά.

εἰ does not introduce direct questions in Attic Greek. For this later use, compare Latin an and even si. The construction is probably due to an ellipse. Winer, 639.