Talmud for Sanhedrin 6:6
נִתְעַכֵּל הַבָּשָׂר, מְלַקְּטִין אֶת הָעֲצָמוֹת וְקוֹבְרִין אוֹתָן בִּמְקוֹמָן. וְהַקְּרוֹבִים בָּאִים וְשׁוֹאֲלִין בִּשְׁלוֹם הַדַּיָּנִים וּבִשְׁלוֹם הָעֵדִים, כְּלוֹמַר שֶׁאֵין בְּלִבֵּנוּ עֲלֵיכֶם כְּלוּם, שֶׁדִּין אֱמֶת דַּנְתֶּם. וְלֹא הָיוּ מִתְאַבְּלִין, אֲבָל אוֹנְנִין, שֶׁאֵין אֲנִינוּת אֶלָּא בַלֵּב:
When the flesh decays [and he has already received atonement through his death and debasement], the bones are gathered and buried in their place [in the ancestral crypts], and the kin (of the deceased) come and solicit the well-being of the judges and of the witnesses, viz.: "We have nothing in our hearts against you, for you judged a righteous judgment." And they would not mourn them (publicly), [so that their debasement be an atonement for them. Others say: Because mourning (aveiluth) obtains when the grave is closed with the top-stone, and at that time they are not mourned, for their atonement is not complete until the flesh is decayed; and since mourning was pushed off, it remains so.] But they would lament them, for "lamentation" (aninuth) is in the heart alone.