Carl Friedrich Keil and Franz Delitzsch Old Testament Commentary

The trial of the people has brought about no purification, no separation of the wicked ones. The trial is viewed under the figure of a long-continued but resultless process of smelting. נחר, Niph. from חרר, to be burnt, scorched, as in Eze 15:4. מאשׁתּם is to be broken up, as in the Keri, into two words: מאשׁ and תּם (from תמם). For there does not occur any feminine form אשּׁה from אשׁ, nor any plural אשּׁת (even אשּׁה forms the plur. אשּׁים), so as to admit of our reading מאשּׁתם or מאשּׁתם. Nor would the plur., if there were one, be suitable; Ew.'s assertion that אשּׁות means flames of fire is devoid of all proof. We connect מאשׁ with what precedes: Burnt are the bellows with fire, at an end is the lead. Others attach "by the fire" to what follows: By the fire is the lead consumed. The thought is in either case the same, only תּם is not the proper word for: to be consumed. Sense: the smelting has been carried on so perseveringly, that the bellows have been scorched by the heat of the fire, and the lead added in order to get the ore into fusion is used up; but they have gone on smelting quite in vain. צרף with indefinite subject, and the infin. absol. added to indicate the long duration of the experiment. In the last clause of the verse the result is mentioned in words without a figure: The wicked have not been separated out (prop., torn asunder from the mass).