John Gill Commentary Ezra 5:11

"And thus they returned us answer, saying, We are the servants of the God of heaven and earth, and are building the house that was builded these many years ago, which a great king of Israel builded and finished." — Ezra 5:11 (ASV)

And thus they returned us answer
To the purpose and in the manner following:

saying, we are the servants of the God of heaven and earth ;
signifying that they were doing his work, in obedience to his will, and to whom they were accountable:

and build the house that was builded these many years ago ;
even five hundred years ago, or thereabout; so that they were not erecting a building where there was none before, but were rebuilding what was in ruins:

which a great king of Israel builded and set up ;
King Solomon, who was a great king for wisdom, honour, riches, peace, prosperity, and extent of his kingdom.