Jerusalem Talmud Shevuot 4:9

משנה: שִׁילַּח בְּיַד עַבְדּוֹ אוֹ שֶׁאָמַר לָהֶן הַנִּתְבָּע מַשְׁבִּיעַ אֲנִי עֲלֵיכֶם שֶׁאִם אַתֶּם יוֹדְעִין לֹו עֵדוּת שֶׁתָּבוֹאוּ וּתְעִידוּהוּ הֲרֵי אֵילּוּ פְטוּרִין עַד שֶׁיִּשְׁמְעוּ מִפִּי הַתּוֹבֵעַ׃ MISHNAH: If he sent through his slave¹⁰³To ask the witnesses to testify. Even though the slave is his personal property and acts as his messenger he is disqualified since he is not the claimant and has no persona in law. or the defendant said to them, “I am putting an oath on you that you shall come and testify for him,” they are not liable unless they hear from the mouth of the claimant¹⁰⁴To create liability, the oath must be delivered directly by the claimant asking for the testimony. Cf. Note 87. Sifra Ḥova (Wayyiqra 2) Parashah 8(4)..

הלכה: שִׁילַּח בְּיַד עַבְדּוֹ כול׳. אָמַר רִבִּי לָֽעְזָר. מַה תַלְמוּד לוֹמַר אִם־לֹא יַגִּ֖יד וְנָשָׂ֥א עֲווֹנוֹ׃ לֹא. מִפִּי הַתּוֹבֵעַ. מַתְנִיתִין צְרִיכָה לְמַה דְאָמַר רִבִּי לָֽעְזָר וּמַה דָמַר רִבִּי לָֽעְזָר צְרִיכָה לְמַתְנִיתִין. אִילּוּ תַנִּינָן וְלֹא תַנָּא רִבִּי לָֽעְזָר הֲוִינָן אָֽמְרִין. יִשְׁמְעוּ מִפִּי הַתּוֹבֵעַ וְלֹא נִשְׁבְּעוּ לַנִּתְבָּע חַייָבִין. הֲוֵי צוֹרְכָה לְמַה דָמַר רִבִּי לָֽעְזָר. אִילּוּ תַנָּא רִבִּי לָֽעְזָר וְלֹא תַנִּינָן הֲוִינָן מָרִין. יִשְׁמְעוּ מִפִּי הַנִּתְבָּע וְלֹא נִשְׁבְּעוּ לַתּוֹבֵעַ חַייָבִין. הֲוֵי צוֹרְכָה לְמַתְנִיתִין וּצְרִיכָה לְמַה דָמַר רִבִּי לָֽעְזָר עַד שֶׁיִּשְׁמְעוּ מִפִּי הַתּוֹבֵעַ וְיִשְׁבְּעוּ לַתּוֹבֵעַ. HALAKHAH: “If he sent through his slave,” etc. Rebbi Eleazar said, why does the verse say, if he does not tell, he has to carry his iniquity? Not¹⁰⁵This is a misquote which makes the text unintelligible. The masoretic text of Lev. 5:8*1 writes the negation as לוֹא which is read both as לוֹ and as לֹא. In the first version, אִם לוֹ יַגִּיד, the liability may only be triggered if he told him, if the claimant personally challenged the witness and if the witness personally accepted the challenge (Babli 35a). In the second version, אִם לֹא יַגִּיד, the liability is triggered if he does not testify., from the mouth of the claimant. Our Mishnah needs what Rebbi Eleazar said, and what Rebbi Eleazar said needs our Mishnah. If we had stated but Rebbi Eleazar had not stated, we would have said that they are liable if they had heard from the claimant but had sworn to the defendant. Therefore what Rebbi Eleazar said is necessary. If Rebbi Eleazar had stated but we had not stated, we would have instructed that they are liable if they heard it from the defendant but had sworn to the claimant. Therefore one needs our Mishnah and needs what Rebbi Eleazar said, only if they heard from the claimant and swore to the claimant.