Exodus 19:10-11

19:10 The Lord said to Moses, “Go to the people and sanctify them ¹  today and tomorrow, and make them wash ²  their clothes 19:11 and be ready for the third day, for on the third day the Lord will come down on Mount Sinai in the sight of all the people.

[19:10]  ¹ tn This verb is a Piel perfect with vav (ו) consecutive; it continues the force of the imperative preceding it. This sanctification would be accomplished by abstaining from things that would make them defiled or unclean, and then by ritual washings and ablutions.

[19:10]  ² tn The form is a perfect 3cpl with a vav (ו) consecutive. It is instructional as well, but now in the third person it is like a jussive, “let them wash, make them wash.”