Hilchot Tefilla - Selichot I

(4) So Moses carved two tablets of stone, like the first, and early in the morning he went up on Mount Sinai, as ה' had commanded him, taking the two stone tablets with him. (5) ה' came down in a cloud—and stood with him there, proclaiming the name ה'. (6) ה' passed before him and “and ה' proclaimed: ‘ה'! a God compassionate and gracious, slow to anger, abounding in kindness and faithfulness, (7) extending kindness to the thousandth generation, forgiving iniquity, transgression, and sin—yet not remitting all punishment, but visiting the iniquity of parents upon children and children’s children, upon the third and fourth generations.” (8) Moses hastened to bow low to the ground in homage, (9) and said, “If I have gained Your favor, O my lord, pray, let my lord go in our midst, even though this is a stiffnecked people. Pardon our iniquity and our sin, and take us for Your own!” (10) [God] said: I hereby make a covenant. Before all your people I will work such wonders as have not been wrought on all the earth or in any nation; and all the people in whose midst you are shall see how awesome are ה's deeds which I will perform for you.

(11) And ה' said to Moses, “How long will this people spurn Me, and how long will they have no faith in Me despite all the signs that I have performed in their midst? (12) I will strike them with pestilence and disown them, and I will make of you a nation far more numerous than they!” (13) But Moses said to ה', “When the Egyptians, from whose midst You brought up this people in Your might, hear the news, (14) they will tell it to the inhabitants of that land. Now they have heard that You, ה', are in the midst of this people; that You, ה', appear in plain sight when Your cloud rests over them and when You go before them in a pillar of cloud by day and in a pillar of fire by night. (15) If then You slay this people as one man the nations who have heard Your fame will say, (16) ‘It must be because ה' was powerless to bring that people into the land promised them on oath that [that god] slaughtered them in the wilderness.’ (17) Therefore, I pray, let my Lord’s forbearance be great, as You have declared, saying, (18) ‘ה' ! slow to anger and abounding in kindness; forgiving iniquity and transgression; yet not remitting all punishment, but visiting the iniquity of parents upon children, upon the third and fourth generations.’ (19) Pardon, I pray, the iniquity of this people according to Your great kindness, as You have forgiven this people ever since Egypt.” (20) And ה' said, “I pardon, as you have asked. (21) Nevertheless, as I live and as ה's Presence fills the whole world, (22) none of those involved—who have seen My Presence and the signs that I have performed in Egypt and in the wilderness, and who have tried Me these many times and have disobeyed Me—

Since we find Scripture saying surely they shall not see the land (v. 23) after salachti ke-devarekha (I have pardoned according to thy word) (v. 20), we learn that the term salach (pardon) refers to being slow to anger. If salach meant full pardon, then the people would have been permitted to enter the land. Similarly, the meaning of ve-nislach lo (and he shall be forgiven) (Num 15:28) is [the punishment shall be held in abeyance] until he fully repents. Salach in all cases means that punishment is not meted out immediately but is delayed. In the case of Num. 15:28, a sacrifice delays punishment and the person is pardoned if he truly repents.

Rabbi Elazar says: It is not possible to say “absolve” (Exodus 34:7) about all transgressions, since “will not absolve” is already stated (Exodus 34:7). And it is not possible to say “will not absolve,” since “absolve” is already stated. How so? The Holy One, Blessed be He, absolves those who repent and does not absolve those who do not repent. Therefore, both “repentance” and “absolve” were mentioned at Horeb.

...on the seventeenth of Tammuz the tablets were broken, on the eighteenth he burnt the calf and punished the of fenders, on the nineteenth he ascended the mountain, as it is said (Exodus 32:30) “And it came to pass on the morrow (the day after he had punished the wrongdoers; cf. vv. 26—29), that Moses said unto the people”, [Ye have sinned a great sin and now I will go up to the Lord]”. There he spent forty days and sought mercy for the people, as it is said, (Deuteronomy 9:18) “And I threw myself down before the Lord [as at the first, forty days and forty nights]”. These terminated on the last day of Ab (there were 11 days from the 19th to the 29th of Tammuz therefore 29 days in Ab complete the forty) and he then returned to the people. On the first day of the New Moon of Ellul it was said to him, (Exodus 34:2) “And be ready in the morning] and go up in the morning unto mount Sinai” — to receive the second tablets. He again spent there the forty days of which it is stated, (Deuteronomy 10:10) “[And I stayed in the mountain, according to the first, days, [forty days and forty nights]”. The words כימים הראשונים, “like the first days”, cannot refer to the number of days for this is stated immediately afterwards; they are to be joined with עמדתי — I stayed in the same state as on the first days: How were the first forty days passed? In God’s good-will (because the Israelites had not yet sinned)! So, too, the last forty days were passed in God’s good-will — from which you must admit that the intervening forty days were passed in God’s anger. On the tenth of Tishri God became reconciled with Israel in joy and perfect affection and said to Moses: “I have forgiven!” and handed him over the second tablets, whereupon Moses went down and began to command them concerning the work of the Tabernacle (cf. Midrash Tanchuma, Ki Tisa 31; Seder Olam 6; Rashi on Exodus 18:13, Deuteronomy 9:18 and also Taanit 36b). They were occupied in its construction until the first of Nisan...