Adding a Yud

The Torah says that when Moses sent the spies into the Land of Canaan, "he called Hosea the son on Nun, 'Joshua'.[1]" Essentially, Moses added the letter yud to the pre-existing name of "Hosea" to become "Joshua." Many commentaries explain[2] that he did so in order for Joshua's name to essential convert Joshua's ordinary name in a theophoric name so that he will be Divinely assisted in carrying out his mission. However, the Targum of Rabbi Jonathan ben Uziel explains, "Moses saw that Joshua was humble and do he changed his name from Hosea to Joshua.[3]" The correlation between humility and the addition of the letter yud to one's name requires further explanation.

When Moses descended from Mount Sinai, the Torah says[4] that his face was shining with rays of light[5]. These "rays of splendor" radiated from Moses' face in such a glowing
fashion that Moses was forced to wear mask so that his people could look at him. The Midrash explains[6] that Moses merited such an honor from Above because when Moses completed writing the Torah, a drop of ink remained in the container, so G-d Himself smeared the remaining droplet on Moses' forehead. This drop of holy ink was the source of Moses' "rays of splendor." However, the Midrash never actually explained what Moses did to merit such a gift from G-d. Furthermore, if the bottle of ink was divinely prepared, then HaShem would have prepared the exact amount of ink needed for the writing of a Torah Scroll, so why would there be extra ink? Rabbi Chaim Ibn Attar (1696-1743) explains[7] that really G-d prepared the precise amount of ink required, yet a morsel remained because Moses was so humble that he did not want to write the verse, "And the man Moses was the most humble…[8]." Instead, Moses wrote the word "humble" without the yud with which it is normally spelled. Therefore, the extra droplet of ink was a result of Moses' humility in not spelling out the word "humble" completely. This extra droplet of ink was the source of Moses' "rays of splendor." Based on this, Rabbi Avraham Yehoshua Heschel of Apta (1755-1825) explains[9] that in deciding on Joshua as Moses' successor, G-d commands Moses, "And you shall put from your own splendor upon him.[10]" Since the source of Moses' own splendor was the extra yud in the word "humble", he added an extra yud to the name of Hosea—making his name Joshua—after he saw that his successor also possessed the trait humility.

The Apta Rov, Rabbi Abraham Joshua Heschel, also explains[11] that the resurrection of the dead will occur in alphabetical order. Thus, those whose first name begins with Aleph will revive before those whose names begin with Beis; and Beis, before Gimmel; etc… Accordingly, when Moses contemplated added an extra Yud to the beginning of Hosea's name, he realized that Hosea could complain that with his new name he would arise from the dead later than with his old name, for yud is five letters after hey—the first letter in Hosea. However, once Moses saw that Joshua was a humble person and worldly matters, such as the order of who will arise from the dead in the future, did not concern him. Consequently, Moses felt that it was appropriate to add an extra yud to the beginning of Joshua's name, for Joshua would not complain due to his unassuming nature of humbleness.

[1] Numbers 13:16
[2] Rashi et al to Numbers 13:16.
[3] Targum Yonason ben Uziel to Numbers 13:16
[4] Exodus 34:29
[5] Some Christians have misunderstood the word Karnei in this verse to mean "horns" instead of "rays"; this error accounts for the medieval artistic depictions of Jews as having horns, an unfortunate misunderstanding which continues to be mistakenly perpetuated.
[6] Exodus Rabbah §47
[7] Ohr HaChaim to Exodus 34:29
[8] Numbers 12:3
[9] See Ohev Yisroel to Parshas Ki See-saw, Exodus 34:29
[10] Numbers 27:20
[11] As quoted by Rabbi Yitzchok Zilberstein in Aleinu L'Shabaech to Numbers 13:16 in the name of Ohev Yisroel-Likutim.