לֹֽא־יָמ֡וּשׁ סֵפֶר֩ הַתּוֹרָ֨ה הַזֶּ֜ה מִפִּ֗יךָ וְהָגִ֤יתָ בּוֹ֙ יוֹמָ֣ם וָלַ֔יְלָה לְמַ֙עַן֙ תִּשְׁמֹ֣ר לַעֲשׂ֔וֹת כְּכָל־הַכָּת֖וּב בּ֑וֹ כִּי־אָ֛ז תַּצְלִ֥יחַ אֶת־דְּרָכֶ֖ךָ וְאָ֥ז תַּשְׂכִּֽיל׃
Janganlah kitab Taurat ini lepas dari mulutmu; renungkanlah isinya siang dan malam, supaya engkau berhati-hati melakukan segala yang tertulis di dalamnya, sebab dengan demikian engkau akan membuat jalanmu berhasil, dan dengan demikian engkau akan bertindak dengan bijaksana.
Shulchan Arukh, Orach Chayim
The one reading the Torah must hold the Sefer Torah at the time one makes the blessing. Gloss: And they base this tradition on the verse from Joshua: "Do not let this Book of Teaching cease from your lips... Be strong and resolute" (Josh. 1:8-9). And from this we have the tradition to say to the person who finishes reading from the Torah, each time: "Chazak" ("Be strong"). (Beit Yosef in the name of Orach Chayyim)