Is one to wash his hands if only his hand entered into the bathroom, such as to close the door?
Yes.<a href="#_ftn1" name="_ftnref1">[1]</a> Some<a href="#_ftn2" name="_ftnref2">[2]</a> rule one is to wash each hand three times. Others<a href="#_ftn3" name="_ftnref3">[3]</a> rule that in such a case washing one time suffices, although one who washes three times is blessed. Practically it is not necessary to be stringent to wash one’s hands three times. Furthermore, some Poskim<a href="#_ftn4" name="_ftnref4">[4]</a> rule that regarding today’s bathrooms one may be lenient not to wash the hands at all in such a case.
<a href="#_ftnref1" name="_ftn1">[1]</a> Torah Leshma 23; Lev Chaim 4:2; Ruach Chaim 3:3; Kaf Hachaim 3:3 and 4:66; Mishneh Yosef 5:6; Yabia Omer 9:108
<a href="#_ftnref2" name="_ftn2">[2]</a> Ruach Chaim 3:3
<a href="#_ftnref3" name="_ftn3">[3]</a> Ben Ish Chaiy Toldos 16 brought in Kaf Hachaim 4:66
<a href="#_ftnref4" name="_ftn4">[4]</a> Lehoros Nasan 7:1; Tzitz Eliezer 7:2; Piskeiy Teshuvos 4:20 footnote 200; See Daas Torah 4

Shulchan Aruch HaRav | ❓Is one to wash his hands if only his hand entered into the bathroom, such as to close the door?

Is one to wash his hands if only his hand entered into the bathroom, such as to close the door? Yes.[1] Some[2] rule one is to wash each hand three times. Others[3] rule that in such a case washing one time suffices, although one who washes three times is blessed.