11 Heb “a generation that did not make firm its heart and whose spirit was not faithful with God.” The expression “make firm the heart” means “to be committed, devoted” (see 1 Sam 7:3).
12 Heb “the sons of Ephraim.” Ephraim probably stands here by synecdoche (part for whole) for the northern kingdom of Israel.
13 Heb “ones armed, shooters of bow.” It is possible that the term נוֹשְׁקֵי (noshéqey, “ones armed [with]”) is an interpretive gloss for the rare רוֹמֵי (romey, “shooters of”; on the latter see 941 I רָמָה). The phrase נוֹשְׁקֵי קֶשֶׁת (noshéqey qeshet, “ones armed with a bow”) appears in 1 Chr 12:2; 2 Chr 17:17.
14 They retreated. This could refer to the northern tribes’ failure to conquer completely their allotted territory (see Judg 1), or it could refer generally to the typical consequence (military defeat) of their sin (see vv. 10–11).
15 Heb “the covenant of God.”
16 Heb “walk in.”

In other versions

ESVEnglish Standard Version

and that they should not be like their fathers,

a stubborn and rebellious generation,

a generation whose heart was not steadfast,

whose spirit was not faithful to God.

The Ephraimites, armed with the bow,

turned back on the day of battle.

They did not keep God’s covenant,

but refused to walk according to his law.

NIVNew International Version (2011)

They would not be like their ancestors—

a stubborn and rebellious generation,

whose hearts were not loyal to God,

whose spirits were not faithful to him.

The men of Ephraim, though armed with bows,

turned back on the day of battle;

they did not keep God’s covenant

and refused to live by his law.

CSBChristian Standard Bible

Then they would not be like their ancestors,

a stubborn and rebellious generation,

a generation whose heart was not loyal

and whose spirit was not faithful to God.

The Ephraimite archers turned back

on the day of battle.

They did not keep God’s covenant

and refused to live by his law.

NLTNew Living Translation

Then they will not be like their ancestors—

stubborn, rebellious, and unfaithful,

refusing to give their hearts to God.

The warriors of Ephraim, though armed with bows,

turned their backs and fled on the day of battle.

They did not keep God’s covenant

and refused to live by his instructions.

LEBThe Lexham English Bible

and not be like their ancestors,

a stubborn and rebellious generation,

a generation that did not make ready its heart,

whose spirit was not faithful to God.

The sons of Ephraim, armed with archers,

turned back on the day of battle.

They did not keep the covenant of God

and refused to go in his law.

KJV 1900King James Version

And might not be as their fathers,

A stubborn and rebellious generation;

A generation that set not their heart aright,

And whose spirit was not stedfast with God.

The children of Ephraim, being armed, and carrying bows,

Turned back in the day of battle.

They kept not the covenant of God,

And refused to walk in his law;

Public Domain