Syntactic Structure
Imperative — v. 7a
ἴσχυε οὖν καὶ ἀνδρίζου — So then be strong! Be a man! (present imperatives 2sg)
↳ Ellipsis
...vv. 7b–7c omitted (to guard and do as Moses commanded; not turning right or left)
Clause 1 — Verb
καὶ οὐκ ἀποστήσεται — and shall not depart (future middle indicative 3sg)
↳ Subject
ἡ βίβλος τοῦ νόμου τούτου — the book of this law
↳ Separation
ἐκ τοῦ στόματός σου — from your mouth
Clause 2 — Verb
καὶ μελετήσεις ἐν αὐτῷ — and you shall meditate in it (future active indicative 2sg)
↳ Time
ἡμέρας καὶ νυκτός — day and night
ἵνα Clause
so that you may understand to do all the things written
↳ Main verb
συνῇς — you might understand (present active subjunctive 2sg, συνίημι)
↳ Complement
ποιεῖν — to do (present active infinitive, object of συνῇς)
↳ Object
πάντα τὰ γεγραμμένα — all the things having been written (perfect passive participle)