לֹֽא־יָמ֡וּשׁ סֵפֶר֩ הַתּוֹרָ֨ה הַזֶּ֜ה מִפִּ֗יךָ וְהָגִ֤יתָ בּוֹ֙ יוֹמָ֣ם וָלַ֔יְלָה לְמַ֙עַן֙ תִּשְׁמֹ֣ר לַעֲשׂ֔וֹת כְּכָל־הַכָּת֖וּב בּ֑וֹ כִּי־אָ֛ז תַּצְלִ֥יחַ אֶת־דְּרָכֶ֖ךָ וְאָ֥ז תַּשְׂכִּֽיל׃
דאָס דאָזיקע בוך פֿון דער תּוֹרה זאָל זיך ניט אָפּטאָן פֿון דײַן מױל, און זאָלסט טראַכטן דערפֿון טאָג און נאַכט, כּדי זאָלסט היטן צו טאָן אַזױ װי אַלץ װאָס שטײט געשריבן דערין; װאָרום דענצמאָל װעסטו מצליח זײַן אין דײַנע װעגן, און דענצמאָל װעסטו באַגליקן.
Rashi
This Sefer Torah.14This Sefer Torah implies a specific Book of the Torah. Which one? Thus Rashi comments that it refers to Sefer Devorim that was before Him. The Sefer Devorim was before Him.
Metzudat David
This. That was said in the text that preceded (verse 7) that Moses commanded you.
Rashi
And you shall meditate in it. Every expression of הִגָיוֹן in the Torah refers to the [meditation] of the heart,15Metsudas Tzion says that הִגָיוֹן sometimes refers to speech as it is written: And my tongue will speak (תֶּהְגֶה) of Your righteousness (Tehillim 35:28). as it is said, ‘And the thoughts of my heart before you;’16Tehillim 19:15. ‘Your heart will give forth fearful thoughts.’17Yeshayahu 33:18.