‘ When he had left, his servants came, and they saw, and behold the doors of the parlour were locked. And they said, “surely he covers his feet in the cooling room”.'
When the servants saw Ehud leave they returned to their duties with the king, but on discovering the door locked, assumed that he was resting and cooling himself, and had locked himself in, wanting to be alone.
“Covering the feet” with long garments was a means of ensuring that nothing was exposed. It was also a phrase used of relieving oneself naturally and carrying out the private functions (1 Samuel 24:3).