|Shabbat Prayer-Do Not Arouse Din-Tzav|
On weeknights we begin Ma'ariv with Ve'hu Rachum, “But He, being full of compassion.” On this matter, Avraham ben Natan haYarchi (Sefer haManhig) wrote, “Since sinners are punished with lashes between afternoon and evening, and since they recite this prayer three times during the flogging, the Prayer–leader proclaims, ' But He, being full of compassion, forgives iniquity and destroys not.”
I do not accept his rationale for reciting the prayer for it is an extraneous one.
He wrote further that, “this is a refutation of the custom of Spain whose fashion it is to recite this prayer on Shabbat and Festivals. However, it is not fitting to recite it because:
the holy day has already arrived and a sinner may not be lashed anymore.
But consider what was said in the Midrash, 'Righteousness lodged in her [Jerusalem] (Isaiah 1:21).” No man who lodged in Jerusalem for a full day could stay possessed of his sin. How so? The morning offering made atonement for transgressions committed at night, and the offering at dusk made atonement for transgressions committed in the daytime.
The prayers were instituted to replace the daily offerings, the morning prayer corresponding to the morning offering, and the afternoon prayer to the offering at dusk, but the evening prayer has no such basis, for there was no offering at night. As it says, in Tav, this week’s portion, “In the day that he commanded the children of Israel to present their offerings (Leviticus 7:38).”
The Rabbis correlated the evening service with the limbs and fat which were not consumed before evening. Of them it is said, “This is the burnt offering; it is that which goes up on his firewood upon the altar all night unto the morning (Leviticus 6:2).” However, if they were consumed by evening, they were consumed, and thus there is no firm sacrificial basis for the evening prayer. Therefore, it is customary to say, “But He, being full of compassion,” for we have no firm sacrificial basis for the evening prayers, and so must seek atonement by means of this prayer. For this reason, the Spanish custom is well and good.
Thus far, the words of haYarchi.
I am astounded at this! For this prayer was established to correspond to the limbs and fat that were not consumed during the daytime; and which could be brought all night. Now, if they happen to be consumed before evening, this did not trouble the Sages; so how can we be troubled by it and recite, “But He, being full of compassion,” for this reason even on Shabbat?
Rather, since the morning prayer replacing the morning offering atones for transgressions committed at night and since the afternoon prayer replacing the daily offering at dusk atones for transgressions committed during the day, the recitation of, "But He, being full of compassion,” is extraneous as a means for atonement.
But the truth of the matter is that this verse was not established to seek the welfare of the living. Rather, it was established to be said during the week to ask for mercy on those souls of the deceased that are judged every night by 3 groups of destructive Angels: Mashchit (Destroyer), Af (Fury), and Cheimah (Wrath) who are mentioned in the verse. It contains 13 words corresponding to the 13 Attributes of Mercy. We ask God that He show mercy to the souls of His creatures for the sake of His 13 attributes, lest the attribute of Din vent its wrath upon them.
On the Shabbat, when Din departs from the world, it is forbidden to say this prayer. Indeed, it is a false plea. For on Shabbat, there is, “rest, quietude and safety.” One who recites the prayer commits a great sin, for he causes Din to be aroused after it had vanished. Through his influence, the Realm of Holiness and Compassion recede into the distance. For all that is aroused below brings about a similar arousal on high, and one should not promote Din on Shabbat. (Sod haShabbat, Section 9)