A.T. Robertson Commentary Mark 8:16

"And they reasoned one with another, saying, We have no bread." — Mark 8:16 (ASV)

They reasoned one with another (διελογιζοντο προς αλληλους), implying discussion. Imperfect tense, kept it up. Matthew 16:7 has εν εαυτοις, in themselves or among themselves.