Be a strong one and courageous one. Chazaq we-amatz. חֲזַק וֶאֱמָץ
A great way to get at the heart of the meaning of a Hebrew term is to find a verse where it’s actually defined for you with counterpart words. In the case of being strong there are quite a few verses where it is defined for us:
Be strong and courageous. Do not be afraid or terrified because of them… Deut. 31:6
And Joshua said to them, “Do not be afraid or dismayed; be strong and courageous. Joshua 10:25
Be strong and courageous. Fear not; do not be dismayed. 1 Chron. 22:13
Being strong in these contexts would mean the opposite of being afraid, terrified, or dismayed. In the English language we usually understand weakness as being the opposite of strength. Strength is the counterpart to fear, and courage is the counterpart to discouragement.
Yet now be strong, O Zerubbabel, declares the LORD. Be strong, O Joshua, son of Jehozadak, the high priest. Be strong, all you people of the land, declares the LORD. Work, for I am with you, declares the LORD of hosts, according to the covenant that I made with you when you came out of Egypt. My Spirit remains in your midst. Fear not.
Haggai 2:4-5
The phrase “When I am weak, then I am strong” (2 Corinthians 12:10) illustrates the conflict between our flesh and spirit. In other words, when our physical body is weak, our inner spirit becomes strong in Christ. When our flesh feels disheartened, we can find courage in the spirit.
636 חָזַק (ḥāzaq) be(come) strong, strengthen, prevail, harden, be courageous, be sore (meaning be severe). (ASV and RSV similar.)
Derivatives
636a חָזָק (ḥāzāq) strong.
636b חֶזְקָה (ḥezqâ) strength (once in the masc. form חֵזֶק (ḥēzeq)).
636c חֹזֶק (ḥōzeq) strength.
636d חֹזְקָה (ḥōzqâ) force.
The basic meaning of this word in the Qal stem is “be(come) strong.” In general, the Piel is causative of the Qal, “make strong,” “strengthen.” The Hiphil is “take hold of,” “seize,” while the Hithpael stem is “strengthen oneself,” hence, “take courage.” The use of ḥāzaq is similar to ʾāmēṣ and ʾāzaz except for the Hiphil which is more like the Qal of ʾāḥaz. This verb is used 291 times.
The Qal form, used eighty-two times, means to “be strong” or “become strong.” In most cases it can be so translated, but often the variety of contexts encourages or necessitates a variety of renditions. Most often the word is used for strength in battle (I Kgs 20:23). The admonition to be strong in combat may simply be an exhortation to be of good courage (and is so translated in II Sam 10:12).
In Gen 41:56 “strong” is used in the sense of “severe” (RSV; KJV and ASV “sore”) in reference to a famine. Similarly a battle may be “severe” (II Kgs 3:26). “To be stronger than” in context comes to mean “prevail,” as the word of David “prevailed” against Joab (II Sam 24:4), David against the Philistine (I Sam 17:50), and Jotham over the Ammonites (II Chr 27:5). When used of Pharoah’s heart the meaning is “harden” (Ex 7:13f.).
Harris, R. L., Harris, R. L., Archer, G. L., & Waltke, B. K. (1999). Theological Wordbook of the Old Testament (electronic ed.) (276). Chicago: Moody Press.
חָזַק chazaq a prim. root; to be or grow firm or strong, strengthen:
חָזָק chazaq from 2388; strong, stout, mighty:—compulsion*(3), fiercest(1), hard(2), harder(1), loud(1), might(1), mighty(20), obstinate*(1), powerful(1), severe(3), stalwart(1), strong(19), stubborn*(1), who is strong(1), who was stronger(1).
Thomas, R. L. (1998). New American Standard Hebrew-Aramaic and Greek dictionaries : Updated edition. Anaheim: Foundation Publications, Inc.
117 אָמֵץ (ʾāmēṣ) be stout, strong, alert, bold, be solid, hard. (KJV, ASV, and RSV translate similarly.)
Derivatives
117a אֹמֶץ (ʾōmeṣ) strength.
117b אַמְצָה (ʾamṣâ) strength.
117c אָמוֹץ (ʾāmôṣ) strong or piebald from.
117d אַמִּיץ (ʾammîṣ) strong.
117e מַאֲמָצָה (maʾămāṣâ) power, strength.
This verb is found forty-one times in the OT. Ugaritic attests a parallel to the term.
In the Piel stem the verb can be rendered “make firm,” “strengthen,” “secure,” “harden” (one’s mind). The Hiphil stem manifests the force of “exhibit strength,” “feel strong.” In the Hithpael stem the translation is “strengthen oneself,” “persist in,” “prove superior to,” “make oneself alert.” The first occurrence of the verb is in Gen 25:23 in the Qal stem. The Lord revealed to Rebekah, before her sons were born, that they would be progenitors of two nations, and that one would be stronger than the other. David sang a song of deliverance for the mercy which the Lord granted in delivering him from Saul, an enemy stronger than he (II Sam 22:18 with its parallel in Ps 18:17 [H 18]). David expressed a similar sentiment in his prayer in the cave (Psa 142:6 [H 7]). In the days of Jeroboam’s revolt against the Davidic dynasty, the Lord defeated the northern kingdom and its forces at the hand of Abijah, and the Judean army “prevailed” despite a well laid ambush (II Chr 13:18).
As a parallel to the more usual verb ḥāzaq, the word is employed repeatedly in God’s charge to Joshua to be strong for the arduous tasks he assumed at the death of Moses (Josh 1:6,7,9,18). Moses spoke similar words of encouragement to his understudy (Deut 31:7, 23). He charged the people in like manner (Deut 31:6).
The Piel stem conveys the concept of making one’s heart obstinate or hard against the right as in the case of Sihon, king of Heshbon (Deut 2:30). The hardening of Pharaoh’s heart before the Exodus is described by two synonymous verbs. Amos employs the same stem in his warning to Israel that, when the Lord commences his visitation in wrath upon them, the strong will not be able to rely on their strength any more than the agile will be able to escape by flight (Amos 2:14).
In a remarkable poetic description of wisdom, the sacred writer indicates that Wisdom was present when God confirmed (made firm) the skies above (Prov 8:28). Joash’s repairs on the temple were successful because of the devotion of the laborers who strengthened the structure (II Chr 24:13). ʾāmēṣ is used in the Piel stem in connection various subjects, including the physical strength of the virtuous woman for her numerous household tasks (Prov 31:17), power for the warrior to carry on his military duties (Nah 2:1 [H 2]), and the strengthening of Rehoboam’s royal power at the defection of the northern tribes (II Chr 11:17). Isaiah’s classic satire on idolatry speaks of how the idolator secures for himself the tree of his choice (Isa 44:14).
The Hithpael serves to designate the strength of the conspirators against Rehoboam (II Chr 13:7), and the determination of Ruth to follow Naomi (1:18).
Harris, R. L., Harris, R. L., Archer, G. L., & Waltke, B. K. (1999). Theological Wordbook of the Old Testament (electronic ed.) (53). Chicago: Moody Press.