It once happened that when Rabbi Yaakov Abu Hasira was in the city of Marrakech, in Morocco, he wanted to have a pair of Tefillin written for him. He inquired if there was an expert and God-fearing scribe in the city. He was told of a Torah scholar who was a masterful scribe, a Kabbalist, and extremely God-fearing - the head of all the scribes in Marrakech. Rabbi Abu Hasira asked that this scribe be brought to him.
When the scribe came, the rabbi asked him to write Tefillin of the finest quality for him, on condition that the scribe immerse in a ritual bath before writing any of the Divine Names, and that he write them with all the kavanot (mystical intentions) of the holy Ari (Rabbi Isaac Luria, one of the leading Kabbalists of all time). He told the scribe not to be concerned about cost, he would pay him whatever he asked (just as it is related of the holy Ari, that he would place a purse filled with money before the scribe, and the scribe would take whatever he wished). The scribe undertook this task, and began to write the Torah passages with the greatest possible precision, paying special attention to the slightest detail. But it happened that the scribe forgot to write one of the Divine Names with any intent at all, and he realized this only after he had finished writing the Tefillin. Since it would have been difficult for him to write them from anew, he told the rabbi nothing. When he presented Rabbi Abu Hasira with the Tefillin, he asked the scribe: "Did you forget the proper intent for this Name, as I sense?" (since he knew this, by Divine insight).
The scribe admitted that this was so. He asked the rabbi`s forgiveness, and undertook to write other Tefillin. The rabbi agreed to this, and the scribe wrote other passages, doing so properly, to the satisfaction of Rabbi Abu Hasira.
We learn from this how great and holy is the commandment of Tefillin, and especially, how the Torah passages must be kosher, that results in the realization of the verse: "And all the peoples of the earth shall see that the Lord`s name is proclaimed over you, and they shall stand in fear of you" (Deuteronomy 28:10).