Joshua 1:8

“This book of the law shall not depart out of thy mouth, etc.] He was often to read it, frequently repeat it, and speak of it, to refresh his own memory with it, and the memory of those about him. Jarchi restrains it to the book of Deuteronomy now before him: but thou shalt meditate therein day and night; whenever he had any leisure from the important business of his office, whether by day or night, (see <190102> Psalm 1:2); that thou mayest observe to do according to all that is written therein; which frequent speaking of it, and constant meditation on it, would lead unto: for then thou shalt make thy way prosperous, and then thou shalt have good success; in his wars with the Canaanites.”

“Out of thy mouth - That is, thou shalt constantly read it, and upon occasion discourse of it, and the sentence which shall come out of thy mouth, shall in all things be given according to this rule. Day and night - That is, diligently study, and upon all occasions consider what is God's will and thy duty. The greatness of thy place and employments shall not hinder thee from this work, because this is the only rule of all thy private actions, and publick administrations. Joshua 1:9”

“1:8 This Book of Instruction (Hebrew torah) probably refers to the book of Deuteronomy (see Deut 4:44; 29:21; 30:10; 31:9-12). It includes Israel’s foundational law codes as well as God’s moral and spiritual instructions. • God commanded Joshua to think and speak of God’s instruction day and night—i.e., continually (cp. Deut 6:6-7; 17:18-20).”

“book: Deu 6:6-9, Deu 11:18, Deu 11:19, Deu 17:18, Deu 17:19, Deu 30:14, Deu 31:11; Psa 37:30, Psa 37:31, Psa 40:10; Psa 119:42, Psa 119:43; Isa 59:21; Mat 12:35; Eph 4:29 thou shalt: Psa 1:2, Psa 1:3, Psa 19:14, Psa 119:11, Psa 119:15, Psa 119:97, Psa 119:99; Pro 2:1-5, Pro 3:1; Col 3:16; Ti1 4:14-16 observe: Deu 5:29, Deu 5:32, Deu 5:33, Deu 6:1-3; Mat 7:21, Mat 7:24, Mat 28:20; Luk 11:28; Joh 13:17, Joh 14:21; Jam 1:22-25; Rev 22:14 have good success: or, do wisely, Jos 1:7 \*marg. Joshua 1:9”