Chasidut for Bava Batra 50:11

This may also be viewed as the allusion of which the Talmud ‎‎Taanit 11 speaks when discussing that during the days of ‎the consecration of the Tabernacle when Moses performed the duties of the High Priest, ‎what garments did he wear? After sending to Ginsak to make ‎enquiries, Mar Ukva was told that Moses wore a white shirt while ‎performing these duties, and that this shirt did not have a border ‎at its lower edge. This comment implied that every tzaddik ‎has his own individual style when serving his Creator. Each style ‎is distinguished by a certain colour. Avraham wore a colour ‎bordering on white, Yitzchok wore a colour bordering on green, ‎whereas Yaakov wore a colour bordering on red. Both Moses and ‎Aaron each wore colours that were unique to them. Similarly, ‎every tzaddik wears a garment tailored to his specific ‎measurements. When these tzaddikim look at the eyn ‎sof, they divest themselves of all that marks them as distinct ‎individuals. The Talmud saying that Moses wore white is an ‎allusion to the eyn sof which is not distinguished by any ‎specific colour, and therefore is perceived as “white,” i.e. as not ‎claiming any specific distinction. All the scientists agree that ‎‎“white” is not a colour, as it is able to accept any dye.
The question regarding what garments Moses wore during ‎the days when he performed the functions of the High Priest ‎although he was not a priest, and therefore was not allowed to ‎wear priestly garments, was therefore being interpreted by the ‎Talmud as quite a legitimate question. The answer given reflects ‎the fact that Moses was spiritually so far above the priests even, ‎that his wearing white, i.e. something that lacked any aspect of ‎ego, of individuality, is a great compliment to Moses. It would not ‎have been appropriate to have mentioned his name, which is ‎after all a reference to his individuality at this time when he was ‎able to face the eyn sof without first having to divest ‎himself of individuality. When the Talmud states that the white ‎shirt worn by Moses during these seven days when he preformed ‎the functions of the priests did not even have a visibly stitched ‎edge at the bottom, this is another allusion to the absence of any ‎sign by means of which it could be identified as his garment, i.e. ‎reference to his individuality.‎
There are tzaddikim who after reaching the level of ‎complete self-negation and attachment to the eyn sof ‎nonetheless revert to a degree of individuality. Moses was not this ‎kind of a tzaddik. He maintained the level of self negation he ‎had achieved, and that is what the Talmud in Baba Batra 25 ‎has in mind when it advises: ‎הרוצה להחכים ידרים‎, loosely translated ‎as “he who wishes to acquire wisdom let him turn southward.” ‎What is meant is that if someone has already progressed ‎spiritually a great deal and he feels he wants to progress still ‎further, in order to get a glimpse of the eyn sof, the closest ‎it is possible for a creature to get to the essence of the Creator, he ‎should strive further upward, the word ‎דרום‎ being understood as ‎if it had been written ‎ד'ר רו'ם‎ ‎‏"‏residing in lofty heights.”‎ ‎