<p>When one washes his hands in middle of the night, even though he plans to return to sleep, he is to discard the water.</p>
<hr class="shulchan-footnotes-sep"><section class="shulchan-footnotes"><div class="shulchan-footnotes-body"><ol><li id="shulchan-fn-1">Shulchan Hatahor 4:1; Zohar Chaiy Vayeishev brought in Piskeiy Teshuvos 1:6: "Leaving the water there is a Sakana and can lead to Keri". <a class="shulchan-fn-back" href="#shulchan-fnref-1" aria-label="Back to text">↩</a></li></ol></div></section>

Shulchan Aruch HaRav | If one washed and plans on going back to sleep, should he discard the water prior to doing so?

When one washes his hands in middle of the night, even though he plans to return to sleep, he is to discard the water.