Mishnah Oholot 16:2: How so? If a spindle was stuck into a wall and [a piece of dead body the size of] half an olive was below it and half an olive above it, even if they are not aligned, it is impure. We see that it spreads impurity to itself in any amount. If a potter was passing with a basket on his shoulder and one side of his overshadowed a grave, vessels on the other side are pure. If there is in the basket a handbreadth's space, they are impure. Mounds of dirt which are close to a city or a road whether new or old are impure, those far, the new are pure and the old are impure. What is considered close? Fifty cubits. What is considered old? Sixty years, says Rabbi Meir. Rabbi Yehuda says close means there are none closer than it and old means that no one remembers [when] it [was created].

כֵּיצַד. כּוּשׁ שֶׁהוּא תָחוּב בַּכֹּתֶל, כַּחֲצִי זַיִת מִתַּחְתָּיו וְכַחֲצִי זַיִת מֵעַל גַּבָּיו, אַף עַל פִּי שֶׁאֵינָן מְכֻוָּנִין, טָמֵא. נִמְצָא מֵבִיא אֶת הַטֻּמְאָה לְעַצְמוֹ בְּכָל שֶׁהוּא. הַקַּדָּר שֶׁהוּא עוֹבֵר וְהַסַּל עַל כְּתֵפוֹ וְהֶאֱהִיל צִדּוֹ אַחַת עַל הַקֶּבֶר, הַכֵּלִים שֶׁבַּצַּד הַשֵּׁנִי טְהוֹרִין. אִם יֵשׁ בַּסַּל פּוֹתֵחַ טֶפַח, טְמֵאִים. הַתְּלוּלִיּוֹת הַקְּרוֹבוֹת בֵּין לָעִיר בֵּין לַדֶּרֶךְ, אֶחָד חֲדָשׁוֹת וְאֶחָד יְשָׁנוֹת, טְמֵאוֹת. הָרְחוֹקוֹת, חֲדָשׁוֹת טְהוֹרוֹת וִישָׁנוֹת טְמֵאוֹת. אֵיזוֹ הִיא קְרוֹבָה, חֲמִשִּׁים אַמָּה. וִישָׁנָה, שִׁשִּׁים שָׁנָה, דִּבְרֵי רַבִּי מֵאִיר. רַבִּי יְהוּדָה אוֹמֵר, קְרוֹבָה, שֶׁאֵין קְרוֹבָה מִמֶּנָּה. וִישָׁנָה, שֶׁאֵין אָדָם זוֹכְרָהּ:

Mishnah Oholot 16:3: One who found a corpse buried normally in the beginning, he may take it along with the surrounding dirt [to be reburied elsewhere]. If he found two [corpses], he may take them along with the surrounding dirt. [If] he found three, if there is between each of them from four to eight cubits, as much as a bier and its gravediggers, this is [considered] a graveyard [and cannot be desecrated]. [Therefore, he must] check from it and all around [for a distance of] twenty cubits. [If] he found one [corpse] a full twenty cubits away, [he must continue] to check from it and all around twenty cubits, because there is an established likelihood, for if in the beginning he found this [same corpse] he would have been able to take it along with the surrounding dirt.

הַמּוֹצֵא מֵת בַּתְּחִלָּה מֻשְׁכָּב כְּדַרְכּוֹ, נוֹטְלוֹ וְאֶת תְּבוּסָתוֹ. מָצָא שְׁנַיִם, נוֹטְלָן וְאֶת תְּבוּסָתָן. מָצָא שְׁלשָׁה, אִם יֵשׁ בֵּין זֶה לָזֶה מֵאַרְבַּע אַמּוֹת וְעַד שְׁמֹנֶה כִּמְלֹא מִטָּה וְקוֹבְרֶיהָ, הֲרֵי זוֹ שְׁכוּנַת קְבָרוֹת. בּוֹדֵק מִמֶּנּוּ וּלְהַלָּן עֶשְׂרִים אַמָּה. מָצָא אֶחָד בְּסוֹף עֶשְׂרִים אַמָּה, בּוֹדֵק מִמֶּנּוּ וּלְהַלָּן עֶשְׂרִים אַמָּה, שֶׁרַגְלַיִם לַדָּבָר. שֶׁאִלּוּ מִתְּחִלָּה מְצָאוֹ, נוֹטְלוֹ וְאֶת תְּבוּסָתוֹ: