Albert Barnes Commentary Nehemiah 6:10

"And I went unto the house of Shemaiah the son of Delaiah the son of Mehetabel, who was shut up; and he said, Let us meet together in the house of God, within the temple, and let us shut the doors of the temple: for they will come to slay thee; yea, in the night will they come to slay thee." — Nehemiah 6:10 (ASV)

Who was shut up - On account, probably, of some legal uncleanness. Compare Jeremiah 36:5.