Yosef's Hair Cut

When Yosef was summoned to Pharaoh to interpret his dreams, it is written [Breishis 41:14]: and he shaved and changed his clothes, and he came to Pharaoh. Onkelos translates the word “shaved” as “vesaper.” It is noteworthy that every other place in the Torah, Onkelos translates it as “yegalchinei.” What is the explanation behind this?

The Rogatchover Gaon answers: It is written [ibid. 49:26]: May they come to Yosef’s head and to the crown of the head of the one who was separated from his brothers. Rabbi Levi understands this verse to mean that Yosef was a nazir. And so we find that from the day that Yosef was separated from his brothers, he did not taste any wine.

Onkelos is therefore troubled: How could it be that Yosef the nazir shaved before he came to Pharaoh? A nazir is forbidden to cut his hair! Onkelos answers that here it was not an actual giluach (hair cutting). His hair was trimmed without the use of a razor, and this is permitted for a nazir to do.