American Standard Version (ASV):
And they kept the charge of their God, and the charge of the purification, and [so did] the singers and the porters, according to the commandment of David, and of Solomon his son.
King James Version (KJV):
And both the singers and the porters kept the ward of their God, and the ward of the purification, according to the commandment of David, [and] of Solomon his son.