כִּי תִשָֹּׂא, כָּךְ פָּתַח רַבִּי תַּנְחוּמָא בַּר אַבָּא (שיר השירים ז, ג): שָּׁרְרֵךְ אַגַּן הַסַּהַר וגו', וְכָל הַפְּתִיחוֹת כֻּלָּן כָּעִנְיָן הַכָּתוּב בַּפָּרָשִׁיּוֹת, וְעוֹד אָמַר לוֹ הַקָּדוֹשׁ בָּרוּךְ הוּא משֶׁה חַיָּבִין לִי יִשְׂרָאֵל מַה שֶּׁלָּווּ הֵימֶנִּי, שֶׁנֶּאֱמַר: כִּי תִשָֹּׂא, כְּמָה דְתֵימָא (דברים כד, י): כִּי תַשֶּׁה בְרֵעֲךָ, אֱמֹר לָהֶם שֶׁיִּפְרְעוּ מַה שֶּׁהֵם חַיָּבִים לִי, הֱוֵי: כִּי תִשָֹּׂא, וַאֲשַׁלְּמָה לָהֶם, שֶׁנֶּאֱמַר (הושע ב, א): וְהָיָה מִסְפַּר בְּנֵי יִשְׂרָאֵל כְּחוֹל הַיָּם.
“When you take a census of the children of Israel, according to their count, each man shall give a ransom for himself to the Lord upon their counting, and there will not be a plague against them upon their counting” (Exodus 30:12). “When you take a census,” this is how Rabbi Tanḥuma bar Abba began: “Your navel is a moon-shaped goblet, [may it not lack mixed wine; your belly is a pile of wheat hedged with lilies]’ (Song of Songs 7:3). All the beginnings, as they are written regarding the Torah portions. Moreover, the Holy One blessed be He said: ‘Moses, Israel owes me what they borrowed from Me, as it is stated: “When you take a census [ki tisa],” just as it says: “When you lend [ki tashe] your neighbor” (Deuteronomy 24:10). Tell them to repay what they owe Me. That is, ki tisa. And I will pay them, as it is stated: “The number of the children of Israel will be like the sand of the sea” (Hosea 2:1).