A.T. Robertson Commentary Luke 2:15

"And it came to pass, when the angels went away from them into heaven, the shepherds said one to another, Let us now go even unto Bethlehem, and see this thing that is come to pass, which the Lord hath made known unto us." — Luke 2:15 (ASV)

Said to one another (ελαλουν προς αλληλους). Imperfect tense, inchoative, "began to speak," each to the other. It suggests also repetition, they kept saying,

Now (δη). A particle of urgency.

This thing (το ρημα τουτο). A Hebraistic and vernacular use of ρημα (something said) as something done. See on Lu 1:65. The ancient Greek used λογος in this same way.