They went to their own company. — Literally, their own people. The statement implies a recognised place of meeting, where the members of the new society met at fixed times.
All that the chief priests. — The word is probably used in its more extended meaning, as including, not only Annas and Caiaphas, but the heads of the four-and-twenty courses (see Note on Matthew 2:4), and others who were members of the Sanhedrin.