Complex sentence: The children were reported to have uttered "bekos" which is Phrygian for "bread", so Psammetichus admitted that the Phrygians were a nation older than the Egyptians.
Split into simpler sentences: The children were reported to have uttered "bekos" meaning "bread" in Phrygian. It was then acknowledged by the Egyptians that the Phrygians were a nation older than the Egyptians.