Keluaran 19:10

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

Keluaran 19:14

19:14 Then Moses went down from the mountain to the people and sanctified the people, and they washed their clothes.

[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.”