Parashas Bamidbar
וּפְקֻדַּ֞ת אֶלְעָזָ֣ר ׀ בֶּן־אַהֲרֹ֣ן הַכֹּהֵ֗ן שֶׁ֤מֶן הַמָּאוֹר֙ וּקְטֹ֣רֶת הַסַּמִּ֔ים וּמִנְחַ֥ת הַתָּמִ֖יד וְשֶׁ֣מֶן הַמִּשְׁחָ֑ה פְּקֻדַּ֗ת כׇּל־הַמִּשְׁכָּן֙ וְכׇל־אֲשֶׁר־בּ֔וֹ בְּקֹ֖דֶשׁ וּבְכֵלָֽיו׃ {פ}
Responsibility shall rest with Eleazar son of Aaron the priest for the lighting oil, the aromatic incense, the regular grain offering, and the anointing oil—responsibility for the whole Tabernacle and for everything consecrated that is in it or in its vessels.
Torah Temimah points to TT / Shabbos (verified).
ופקדת אלעזר — המוציא בשבת בין בימינו בין בשמאלו בתוך חיקו או על כתיפו חייב, שכן משא בני קהת.
English: “And the charge of Elazar” — one who carries out on Shabbos, whether in his right hand or his left, in his bosom or on his shoulder, is liable, for thus was the burden of the sons of Kehas.
Custom
Chazal expand the liability for carrying on Shabbos from the model of the Kehasite burden.