Musar zu Tehillim 126:2

And when should a person rejoice greatly and laugh? When the Divine Presence returns to Zion, for this is a great joy, as it is written "Then will our mouths be filled with laughter and our tongues with song; then will they say among the nations, 'The Lord has done great things with these' " (Ps. 126:2).

When one can pay "lip-service" – as in the case of the substitution of prayer for the sacrifice – one's lips move normally and do not display a sign that their owner grieves over the fact that he has to content himself with such "lip-service." Nowadays, when in exile, our "lip-service" is accompanied by our lips becoming painfully distorted when we really grieve over our inability to fulfil our duty in the optimal manner. To contrast this experience with the way we shall feel after the Temple will be restored, David says in Psalms 126,2: אז ימלא שחוק פינו ולשוננו רנה, "Then our mouths shall be filled with laughter and our tongues with songs of joy."

Rabbi Yochanan said (Berachos 31a): “It is forbidden to fill one’s mouth with laughter in this world, as it is stated, ‘Then [in the future] our mouth will be fill with laughter’ (Tehillim 126:2).” The Rabbis said of Rabbi Shimon ben Lakish that from the moment he heard this from Rabbi Yochanan he never again filled his mouth with laughter.

To get back to the subject of the cruse made of earthenware to be eventually exchanged for the קרן, horn. Not only will the פך be traded for a קרן in the future, but even the כף will undergo תיקון, metamorphosis, and instead of representing כף חובה, the side of the scale containing our debits, will become כף זכות, the side of the scale containing our merits. When the princes each brought their offerings on the occasion of the dedication of the Holy Tabernacle recorded in Numbers chapter 7, each one of them brought כף אחת מלאה קטורת, one spoonful of incense. The princes alluded to the תיקון, rehabilitation of original man, by each one including in their offering a bowl of silver weighing 130 (unspecified units of silver) thus alluding to the 130 years that Adam had failed to perform the commandment to be fruitful and to multiply. Rashi elaborates on this theme in Numbers 7,19. In Psalms 139,5: ותשת עלי כפכה, "You have laid Your hands upon me," we find an allusion to the diminution of man to the numerical equivalent of one hundred=כף, something caused by the serpent, as we know from Exodus 4,4 when G–d showed Moses that his staff turned into a serpent while in his כף. In the future we will witness fulfillment of Kings II 11,12: ויכו כף, ויאמרו יחי המלך, "They clapped their hands and shouted "long live the king!" (The subject dealt with is the crowning of Yoash, last surviving member of the Davidic dynasty after Athaliah had murdered all the others. Yoash's reign ushered in a rejuvenation of the kingdom of Yehudah under a king loyal to G–d and tutored by a pious High priest Yeho-yadah.) The כף in the verse quoted symbolizes the positive aspect of the word, and is an allusion to a similar event of far greater dimensions in the future. The כף full of incense, would be offered by Aaron (or his sons if suitable) in the Holy of Holies on the Day of Atonement. The כף will be כפופה, closed, because when we are worthy we will experience the blessing of Deuteronomy 15,4 that there will not be anyone who is destitute (in need of a כף פתוחה, a handout from an open hand). The פ in that word which is open, will reflect the emotions expressed in Psalms 126,2 which deals with the return of G–d to Zion, and which describes our mouths as filled with laughter and joy.

David goes on: "One may lie down weeping at nightfall; but in the morning there are shouts of joy." Why did David not contrast "weeping" with שחוק, "laughter?" After all Solomon in Kohelet 3,4 describes the opposite of weeping as laughter. When David mentions that by morning there will be "joy," he thereby tells us something that goes beyond the antithesis of weeping. Rabbi Moshe Alshich has explained this in his commentary on Psalms 126,2, where he says that the joy referred to at the time under discussion in that Psalm will spill over from the mouth (lips) to the tongue. It is only by a miracle that the tongue can rejoice at a time when the mouth is full of laughter. When the Gentile nations observe this, (126,3) they will comment that G–d has indeed done great things for the Jewish people. At any rate, the trials do not last longer than from evening to morning.