Verse 4: Yet he restored the money unto his mother; and his mother (Is. 46:6) took two hundred shekels of silver, and gave them to the founder, who made thereof a graven image and a molten image: and they were in the house of Micah.
Yet he restored the money unto his mother; though his mother allowed him to keep it, yet he persisted in his resolution to restore it, that she might dispose of it as she pleased; and did actually restore it, as was said before; and now confirms the former restitution, and therefore is twice said to restore it.
[She took two hundred silver pieces] Question: What was done with the rest? Responses: 1. All the remaining shekels she kept for herself. Whence her son Micah provided from his own wealth that an Ephod and other idols be made (Lapide out of Montanus’ Commentary). 2. The remaining sum of money was to be gathered in the shrine, and it appears to have been spent on the Ephod, and the remaining sacred idol apparatus (Menochius, similarly Bonfrerius). Or, she gave two hundred silver pieces to the silversmith as the price, and she put out the rest for forming the graven and cast thing. She also made a temple, etc. (Munster).
His mother took two hundred shekels of silver; reserving nine hundred shekels, either for the ephod and teraphim, or for other things relating to this worship, or for her own private use; being, it seems, cooled in her first zeal, and willing to have as cheap a religion as she could, as also her son Micah was, verse 10.
[She gave to the silversmith (thus Pagnine, Montanus), לַצּוֹרֵף] Ἀργυροκόπῳ, that is, a sculptor of silver (Septuagint), a goldsmith (Syriac, Arabic), caster (Junius and Tremellius), a metal-caster (Munster, Vatablus, Drusius). Who first poured that, and then sculpted it (Drusius).
Who made thereof; made them, either first, of that matter; or secondly, for that money.
 Hebrew: וַיָּ֥שֶׁב אֶת־הַכֶּ֖סֶף לְאִמּ֑וֹ וַתִּקַּ֣ח אִמּוֹ֩ מָאתַ֙יִם כֶּ֜סֶף וַתִּתְּנֵ֣הוּ לַצּוֹרֵ֗ף וַֽיַּעֲשֵׂ֙הוּ֙ פֶּ֣סֶל וּמַסֵּכָ֔ה וַיְהִ֖י בְּבֵ֥ית מִיכָֽיְהוּ׃
 צָרַף signifies to smelt or refine.