וְכֹ֨ל אֲשֶׁר־יִגַּ֜ע עַל־פְּנֵ֣י הַשָּׂדֶ֗ה בַּֽחֲלַל־חֶ֙רֶב֙ א֣וֹ בְמֵ֔ת אֽוֹ־בְעֶ֥צֶם אָדָ֖ם א֣וֹ בְקָ֑בֶר יִטְמָ֖א שִׁבְעַ֥ת יָמִֽים׃
И всякий, кто в открытом поле коснется того, кто убит мечом, или того, кто умирает от себя, или кости человека, или могилы, будет нечистым семь дней.
Mishnah Pesachim
Rabbi Hanina the vice-chief of the priests says: during all of the days of the priests they never refrained from burning [sacrificial] meat which had been defiled by an offspring of uncleanness with meat which had been defiled by a father of uncleanness, even though they add uncleanness to its uncleanness. Rabbi Akiva added and said: during [all] the days of the priests they did not refrain from lighting oil which had been rendered unclean by a tevul yom in a lamp which had been made unclean by one who had contracted corpse impurity, even though they add uncleanness to its uncleanness.
Mishnah Eruvin
One may make the side-posts out of anything, even something that is alive. But Rabbi Yose prohibits this. It also causes defilement as the covering of a tomb, But Rabbi Meir makes pure. One may write on them gittin, But Rabbi Yose the Galilean declares it unfit.
Mishnah Eduyot
Rabbi Hanina, chief of the priests, testified concerning four matters:Through all their days the priests never refrained from burning meat which had been defiled by an “offspring” of impurity with meat which had been made impure by a “father” of impurity, although they were [thereby] increasing its impurity by a [higher] impurity. Rabbi Akiba added: “Through all their days the priests never shrank from lighting oil which had been rendered unfit by a tevul yom in a lamp made impure by one who was made impure by a corpse, although they were [thereby] increasing its impurity by a [higher] impurity.”