הַמְעַ֣ט מִכֶּ֗ם כִּֽי־הִבְדִּיל֩ אֱלֹהֵ֨י יִשְׂרָאֵ֤ל אֶתְכֶם֙ מֵעֲדַ֣ת יִשְׂרָאֵ֔ל לְהַקְרִ֥יב אֶתְכֶ֖ם אֵלָ֑יו לַעֲבֹ֗ד אֶת־עֲבֹדַת֙ מִשְׁכַּ֣ן יְהוָ֔ה וְלַעֲמֹ֛ד לִפְנֵ֥י הָעֵדָ֖ה לְשָׁרְתָֽם׃
is it but a small thing unto you, that the God of Israel hath separated you from the congregation of Israel, to bring you near to Himself, to do the service of the tabernacle of the LORD, and to stand before the congregation to minister unto them;
Rashi on Numbers
ולעמד לפני העדה AND TO STAND BEFORE THE CONGREGATION to sing on the Duchan (the Platform).
Sforno on Numbers
ולעמוד לפני העדה לשרתם, to serve the Lord by representing the whole community by carrying the sacred vessels, and parts of the Tabernacle. G’d selected you to perform this service לפני העדה, in full view of the whole community to serve as a reminder that another group of your nation, the firstborn, had already been deprived of this privilege due to their having participated in the sin of the golden calf, and you had been chosen to replace them.
Rabbeinu Bahya
המעט מכם, “is it too little for you?” Moses asked if their selection as Levites and their performing duties in and around the Tabernacle was considered by them as something so insignificant?