Fifty Gates Of Binah
בענין המסעות שתלה הכתוב ביציאת מצרים נראה דכמו שנזכר יצ"מ נ' פעמים בתורה כמ"ש בזוה"ק לרמוז שיצאו ממ"ט שערי טומאה ונכנסו בנ' שערי בינה
Regarding the journeys, which the verse links to the Exodus from Mitzrayim, it appears that just as Yetzias Mitzrayim is mentioned fifty times in the Torah—as the Zohar HaKadosh states—this hints that Bnei Yisrael went out from the forty-nine gates of impurity and entered the fifty gates of binah (understanding).
The Torah ties the listing of Bnei Yisrael's journeys to the Exodus. The Sfas Emes opens by noting that Yetzias Mitzrayim appears fifty times in the Torah, corresponding to leaving the forty-nine levels of impurity and entering the fifty gates of binah.
וכמו כן יש נ' שבתות בשנה שבכל שבת נפתח אחד משערי בינה הנ"ל
And similarly, there are fifty Shabbosos in the year, for on each Shabbos one of these aforementioned gates of binah is opened.
The same pattern of fifty appears in the year's Shabbosos. Each Shabbos opens one of those fifty gates of understanding.
כמו כן הי' באלה נ' מסעות לפי מ"ש רש"י שחזרו לאחוריהן ח' מסעות נמצא שהם חמשים
So too it was with these journeys: according to what Rashi writes, that they turned back eight journeys, it emerges that they total fifty.
The pattern of fifty also shows up in the journeys themselves. Counting Rashi's eight return-journeys brings the total of journeys to exactly fifty.
ויתכן שזו המסע האחרונה בעבר הירדן הי' מול שער הנ'
And it stands to reason that this final journey, on the eastern side of the Yarden, was opposite the fiftieth gate.
Building on that count, the Sfas Emes suggests the very last journey aligned with the highest, fiftieth gate.
ולפי שכתבו חז"ל שנמסרו למרע"ה נ' שערים חוץ מאחד ותחסרהו מעט מאלקים לכן במסע זו כתיב מעשה בנות צלפחד שנעלם הדין ממרע"ה [וכן מצאתי ברבינו בחיי]. ויש רמז לזה במ"ש ויקרב משה את משפטן בנון ארוכה לרמוז שהי' מעין שער הנ' שהוא גבוה מכל השערים לכן נעלם ממנו
And since Chazal wrote that fifty gates were given over to Moshe Rabbeinu except for one—"and You made him a little less than the angels" (Tehillim 8:6)—therefore in this journey the verse records the episode of the daughters of Tzelafchad, in which the halachah was hidden from Moshe Rabbeinu [and so too I found in Rabbeinu Bachya]. And there is a hint to this in what is written, "And Moshe brought their case near" (Bamidbar 27:5), with an elongated nun, to hint that it was of the nature of the aforementioned fiftieth gate, which is loftier than all the gates, and therefore it was hidden from him.
Moshe Rabbeinu received forty-nine gates of binah but the fiftieth remained beyond him. This explains why precisely at this final journey the Torah places the case of Tzelafchad's daughters, where the ruling was hidden from Moshe—and the verse hints at the loftiness of the fiftieth gate with the enlarged nun in 'vayakrev.'
ויתכן ג"כ לומר כי בזו הבחי' עברו את הירדן וידוע כי בקיעת הירדן הי' בעשור לחודש ניסן
And it is also fitting to say that with this very level they crossed the Yarden, and it is known that the splitting of the Yarden took place on the tenth of the month of Nisan.
The crossing of the Yarden was reached through this same elevated level. The Sfas Emes notes the crossing occurred on the tenth of Nisan.
והיא בחי' שבת הגדול שהוא שבת הנ' משבתות השנה כמ"ש שם מזה:
And this is the aspect of Shabbos HaGadol, which is the fiftieth Shabbos of the Shabbosos of the year, as is explained there concerning this matter.
That date connects to Shabbos HaGadol, which corresponds to the fiftieth Shabbos of the year. Thus the theme of the fiftieth gate ties together the journeys, the Yarden, and Shabbos HaGadol.
Summary: The Sfas Emes builds his entire piece around the recurring motif of the number fifty, which represents the gates of binah that Bnei Yisrael attained upon leaving the forty-nine gates of impurity in Mitzrayim. He shows this pattern in three places: Yetzias Mitzrayim is mentioned fifty times in the Torah, there are fifty Shabbosos in the year that each open a gate of understanding, and—counting Rashi's eight return-journeys—the travels of Bnei Yisrael also total fifty, with the final journey aligned opposite the highest fiftieth gate. Because Moshe Rabbeinu received only forty-nine gates and the fiftieth was withheld from him, the Torah fittingly places the episode of Tzelafchad's daughters at this final journey, where the halachah was hidden from him, hinted at by the elongated nun in 'vayakrev Moshe.' Finally, the Sfas Emes connects the crossing of the Yarden on the tenth of Nisan to Shabbos HaGadol, the fiftieth Shabbos of the year, weaving all these strands into the single theme of reaching toward the loftiest gate of binah.