Midrash for Numbers 31:17

(Bamidbar 31:17) "And every woman knowing a man for carnal relations, kill": Is Scripture speaking of a woman who is fit for intercourse or of one who has actually had intercourse? (Ibid. 31:18) "And all the little ones among the women who did not know carnal relations, keep alive for yourselves" makes it clear that the criterion is being fit for intercourse. (31:7) "kill": Why is this (second "kill") mentioned? (i.e., Why is the first "kill" not sufficient to include "and every woman knowing a man"?) (It is written) to conclude the subject (i.e., to be included with the preceding part of the verse.) For otherwise, I would not know whether (the reading is to kill the women together) "with every male among the little ones" or to keep (them) alive "with all the little ones among the women." It (the second "kill") is, therefore, written (to conclude the subject of the first verse.) "And all the little ones among the women who did not know carnal relations, keep alive for yourselves": From here R. Shimon b. Yochai ruled. A proselytess who was converted at less than three years and one day is fit for (marriage to) the priesthood.