Exodus 30:12

כי תשא This has the meaning of obtaining: WHEN THOU TAKEST [THE SUM], (not of “lifting up” as in Genesis 40:13); as the Targum has it, תקבל. The sense is: when you wish to obtain the sum total of their number — to know how many they are — do not take their census by their polls but each of them shall give half a shekel, and you shall count these, and so ascertain their number. ולא יהיה בהם נגף THAT THERE BE NO CALAMITY AMONG THEM — for numbers (i. e. things that have been numbered) are subject to the influence of the “evil eye”, and therefore if you count them by their polls pestilence may befall them, as we find happened, in the days of David (II Samuel 24:10 and 15).

When thou dost take the sum of the children of Yisra᾽el after their number, then shall they give every man a ransom for his soul to the Lord, when thou dost number them; that there be no plague among them, when thou dost number them.

כִּ֣י תִשָּׂ֞א אֶת־רֹ֥אשׁ בְּנֵֽי־יִשְׂרָאֵל֮ לִפְקֻדֵיהֶם֒ וְנָ֨תְנ֜וּ אִ֣ישׁ כֹּ֧פֶר נַפְשׁ֛וֹ לַיהֹוָ֖ה בִּפְקֹ֣ד אֹתָ֑ם וְלֹא־יִהְיֶ֥ה בָהֶ֛ם נֶ֖גֶף בִּפְקֹ֥ד אֹתָֽם׃