1 Chronicles 15:27

And David was clothed with a robe of fine linen
For though a king, he, being among the singers, was clothed as they; for so it follows:

and all the Levites that bare the ark, and the singers, and Chenaniah
the master of the song;
or of those that bore the burden, the ark, as the Targum:

with the singers;
all were clothed in robes of fine linen:

David also had upon him an ephod of linen;
which he had besides his linen robe, and was over it; and being a shorter and tighter garment, it bound the other closer to him; though some think this is explanative of the former, and designs the same, and is what others, besides priests, were, on occasion, allowed to wear, see ( 1 Samuel 2:18 ) .