Musar para sa Genesis 28:17

ויירא ויאמר מה נורא המקום הזה. It is appropriate for man to stand in awe and reverence at sites which have been distinguished through historical events and which hosted holy people, or which themselves represent holiness. This is is why idle conversation in houses of study and synagogues is forbidden even when no study or prayer is in progress. Such conversation interferes with one's reverence and thereby aggravates the wrong committed.

"In Your awe" - that is Yaakov, as about him is it written (Genesis 28:17), "how awesome is this place."

Let me now explain how the twelve tribes and the building, destruction of, and rebuilding of the Holy Temple are all alluded to in the dream. Rabbi Shimon bar Yochai is quoted in Bereshit Rabbah 69,7 that the Holy Temple in the Celestial Regions is only eighteen miles higher than its counterpart on earth. He bases this on 28,17, where Jacob says: וזה שער השמים, "This is the gateway to Heaven." The numerical value of 18 =וזה. Another version of the meaning of this verse quoted in the same Midrash, says that G–d showed Jacob the Temple built, destroyed and rebuilt. Upon seeing this, Jacob exclaimed: מה נורא המקום הזה, "How awesome is this place!" The expression corresponds to Psalms 68,36 נורא אלוקים ממקדשיך, "G–d You are awesome in Your holy places." The latter expression אין זה, corresponds to Lamentations 5,17: על זה היה דוה לבנו, "Because of this (the destruction of the Temple) our hearts are sick." The words אין זה, are associated only with חרב, destruction. The allusion to the rebuilding of the Temple in the future is based on the use of the word שער in our verse and the corresponding use of that word in Psalms 147,13: כי חזק בריחי שעריך, "For He made the bars of your gates strong."