[21:11] 1 tn The verb שָׁלַח (shalakh) means “to send forth,” but in the Piel “to release; to allow to run free.” The picture of children frolicking in the fields and singing and dancing is symbolic of peaceful, prosperous times.
[21:12] 2 tn The verb is simply “they take up [or lift up],” but the understood object is “their voices,” and so it means “they sing.”