Rashi

shall play Heb. וְשִׁעֲשַׁע, shall play. over the hole of an old snake over a hole in the ground in which the snake makes its nest [krot in O.F.], a cave. an old snake פֶּתֶן. A snake, when it ages, becomes deaf and is called פֶּתֶן. From then on, it cannot be charmed; as it is said (Psalms 58:6): “Who will not hearken to the voice of charmers.” and over the eyeball of a venomous snake Jonathan renders: the eyeballs of venomous snakes [מְאוּרַת from אוֹר, light]. Menahem (Machbereth Menachem p. 32) interpreted it as an expression of a hole, namely holes in the ground. Comp. (Gen. 11:28) “The valley of the Chaldees (אוּר)”; (infra 24:15) “In the valleys (בָּאוּרִים) honor the Lord.” a weaned child a child weaned from his mother’s breasts. shall stretch forth his hand Heb. הָדָה. Jonathan renders: shall stretch forth his hands (sic). Comp. (Ezekiel 7:7) “The joyful call (הֵד) of the mountains, also (infra 16: 9) “The cry (הֵידָד),” which is an expression of raising the voice. This, too, is an expression of raising, and the final [letter] ‘heh’ appears in it as a radical which sometimes falls out, like עָשָׂה (made), בָּנָה (built), קָנָה (acquired).