Original Word: ἴσθι
Part of Speech: Verb (Imperative)
Transliteration: isthi
Pronunciation: EES-thee
Phonetic Spelling: (is'-thee)
KJV: + agree, be, X give thyself wholly to
Word Origin: [second person imperative present of G1510 (εἰμί - am)]

1. be thou

agree, give thyself wholly to.

Second person imperative present of eimi; be thou -- + agree, be, X give thyself wholly to.

see GREEK eimi

Word Origin
imper. of eimi, q.v.

Form and Grammatical Function

ἴσθι is the singular present imperative of the Greek verb of existence. As an imperative it issues a direct command for a person to “be” something. Rather than calling for an external action, it summons an inward posture or settled state.

Presence in the Canon

Strong’s system lists no occurrences of ἴσθι under number 2468 in the Greek New Testament, because each instance is catalogued under the root 1510. Nonetheless, the form itself stands behind many familiar commands in both Testaments, especially in the Septuagint. The following survey highlights representative texts where the imperative “be” shapes the biblical message:

• Genesis 17:1 – “Walk before Me and be blameless.”
• Deuteronomy 31:6 – “Be strong and courageous; do not be afraid or terrified of them.”
• Joshua 1:9 – “Be strong and courageous. Do not be afraid; do not be discouraged.”
• Isaiah 41:10 – “Do not fear, for I am with you; do not be afraid, for I am your God.” (LXX employs ἴσθι to express “be not afraid.”)
• Matthew 5:25 – “Reconcile quickly with your adversary…” (Greek: ἴσθι εὐνοῶν, “be well-disposed.”)
• Luke 8:50 – “Do not be afraid; only believe, and she will be healed.”
• 1 Peter 1:15 – “But just as He who called you is holy, so be holy in all you do.”

Theological Emphasis

1. Identity before Activity

God routinely grounds ethical commands in declared identity. “Be blameless” follows the self-revelation “I am God Almighty” (Genesis 17:1). The imperative to “be holy” rests on the statement “for I am holy” (1 Peter 1:16). Thus ἴσθι frames holiness as the believer’s God-given identity, not a self-generated moral improvement.

2. Covenant Assurance

Every “be” command is coupled with divine presence: “for the LORD your God will be with you” (Joshua 1:9). The grammar underscores that courage flows from communion, not mere human resolve.

3. Inner Transformation

ἴσθι moves the focus from doing to becoming. Scripture consistently presses beyond external conformity to inward reality—be blameless, be reconciled, be strong, be at peace. The new covenant promise of a changed heart (Jeremiah 31:33) finds imperatival expression in such commands.

4. Christological Fulfillment

Jesus’ own “I am” declarations (John 8:58; 14:6) reveal Him as the ground of all existence. When He commands, “Do not be afraid; only believe” (Luke 8:50), the imperative rests on His sovereign ability to give life. In Him believers receive both the command and the capacity to obey (Philippians 2:13).

Historical Reception

Early Church teachers drew pastoral comfort from the imperative “be.” Ignatius exhorted, “Be steadfast as an anvil” (To Polycarp 6), echoing 2 Timothy 2:3. Augustine preached that Christ says “Be what you are—my body” to emphasize participation in the divine life. The Reformers highlighted Gospel imperatives as calls grounded in the finished work of Christ rather than self-salvation.

Ministry and Discipleship Applications

• Preaching: Use ἴσθι-based texts to show that God first establishes identity (“saints,” “beloved”) and then commands corresponding life.
• Counseling: The command “be reconciled” (Matthew 5:25) provides a Christ-centered model for conflict resolution—swift, humble, and relational.
• Leadership: Joshua 1:9 offers a template for commissioning servants—affirm divine presence, then call for courage.
• Spiritual Formation: Encourage believers to meditate on “be holy” (1 Peter 1:15-16), praying for Spirit-wrought transformation rather than mere rule-keeping.

Related Imperatives

Plural forms (ἔστε) broaden the same concept to the community (e.g., “You are the salt of the earth… be at peace with one another” in Mark 9:50). Volitional negatives often appear with μή (“Do not be afraid”), reinforcing trust over fear.

Conclusion

Though Strong’s number 2468 records no separate New Testament hits, ἴσθι resonates through Scripture as God’s authoritative call for His people to embody the character, courage, and holiness that He Himself supplies. Each imperative “be” is a summons into the life He grants, enabling believers to reflect His own eternal “I AM” in their daily walk.

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