Genesis 21:16

מנגד means some distance away. כמטחוי קשת AS IT WERE A BOWSHOT — about two bowshots (since the first word is really plural) (Genesis Rabbah 53:13). The word signifies shooting an arrow — we find it so used in the Mishna (Sanhedrin 46a). If you say that it should have been written כמטחי קשת (since the root is טחה) then I say that it is quite regular for a ו to be inserted in these forms as (Song 2:14) “in the clefts (בחגוי) of the rock”, where בחגוי is of the same derivation as חגא in (Isaiah 19:17) “And the land of Judah shall become a breach (לחגא) to Egypt” and of the same derivation as יחוגו in (Psalms 107:27) “They reeled (וחוגו) to and fro and staggered like a drunken man”. Similar, also, is (Psalms 65:6) “The ends of (קצוי) the earth” which is of the same derivation as ,קצה, end. ותשב מנגד SHE SAT AT A DISTANCE — (this is the second time that it is so said) — now that he came nearer to death she moved further away from him.

וַתֵּ֩לֶךְ֩ וַתֵּ֨שֶׁב לָ֜הּ מִנֶּ֗גֶד הַרְחֵק֙ כִּמְטַחֲוֵ֣י קֶ֔שֶׁת כִּ֣י אָֽמְרָ֔ה אַל־אֶרְאֶ֖ה בְּמ֣וֹת הַיָּ֑לֶד וַתֵּ֣שֶׁב מִנֶּ֔גֶד וַתִּשָּׂ֥א אֶת־קֹלָ֖הּ וַתֵּֽבְךְּ׃

And she went, and sat her down over against him a good way off, as it were a bowshot: for she said, Let me not see the death of the child. And she sat over against him, and lifted up her voice, and wept.