וַיִּתֵּ֨ן יְהוָ֜ה אֵלַ֗י אֶת־שְׁנֵי֙ לוּחֹ֣ת הָֽאֲבָנִ֔ים כְּתֻבִ֖ים בְּאֶצְבַּ֣ע אֱלֹהִ֑ים וַעֲלֵיהֶ֗ם כְּֽכָל־הַדְּבָרִ֡ים אֲשֶׁ֣ר דִּבֶּר֩ יְהוָ֨ה עִמָּכֶ֥ם בָּהָ֛ר מִתּ֥וֹךְ הָאֵ֖שׁ בְּי֥וֹם הַקָּהָֽל׃
Y dióme el Señor las dos tablas de piedra <span class="x" onmousemove="Show('perush','El Rambam explica esta parte del versículo en el <b>1º Capítulo</b> de Las Leyes de los Fundamentos de la Torá.',event);" onmouseout="Close();">escritas por el dedo de Dios</span>; y en ellas estaba escrito conforme a todas las palabras que os habló el Señor en el monte de en medio del fuego, el día de la asamblea.
Rashi
לוחת TABLETS — This word is written without a ו before the ת, so that it may be read לוחת (a singular form), to indicate that both of them were alike (Midrash Tanchuma, Eikev 10; cf. Rashi on Exodus 31:18 and Note thereon).
Ibn Ezra
The word with the finger has already been explained [comment on Exodus 31: 18].
Or HaChaim
כתבים באצבע אלוקים, "written with the finger of G'd." We need to understand what is meant by ועליהם, "and upon them." I have explained in Exodus 31,18 that the words: "written with the finger of G'd" mean that G'd's finger was pointed at the place on the Tablets where the particular letter was to be inscribed and that in this fashion the letter appeared engraved and this is the meaning of חרות על הלוחות, "engraved on the Tablets." Our verse tells us that whereas the area of the outline of the letter on the Tablets remained engraved, the hollow projected a light which emanated from the finger of G'd and appeared on the surface of the Tablets so that the letters appeared as if written on the Tablets though in fact they were engraved. This is what Moses meant when he spoke of ועליהם ככל הדברים אשר דבר השם, "and upon them like all the words G'd had said." The letter כ describes the result of G'd's engraving the Tablets, i.e. that the letters appeared visible as light on the surface of the Tablets.