דברי הימים ב, פרק כ״ה, פסוק ז׳

Before launching a military campaign, the king of Judah decides to hire warriors from the neighboring Northern Kingdom of Israel to bolster his ranks. However, divine providence intervenes to halt this plan. A prophet arrives to deliver a stern warning against the alliance, cautioning that joining forces with the northern tribes will guarantee defeat due to their spiritual decay.

The prophet arrives as an unnamed messenger of God [ביאור שטיינזלץ]. Yet, ancient tradition identifies this figure as Amoz, the father of the prophet Isaiah [רד״ק]. He presents the king with a clear and uncompromising demand: the soldiers from Israel must not join the Judean army.

The reasoning behind this prohibition is both spiritual and military. God does not stand with the northern fighters because they have abandoned His ways [ביאור שטיינזלץ]. The prophet presents the king with two possible mindsets regarding warfare, both leading to the exact same conclusion [מלבי״ם]. If the king is truly relying on God for victory, he must recognize that the laws of war dictate that those burdened by sin are unfit for combat and must be sent home. Alternatively, if the king is simply relying on natural military tactics and the sheer number of troops, the prophet warns that these sinful soldiers will provide no strategic advantage anyway.

The northern kingdom of the ten tribes is specifically referred to as the children of Ephraim. The primary approach among commentators is that this title stems from their first king, Jeroboam, who was from the tribe of Ephraim. However, this name serves as more than just a tribal marker; it highlights the root cause of their spiritual abandonment. Jeroboam was the one who initially led the kingdom into the sin of worshipping golden calves. By doing so, he established a spiritual barrier that distanced the people from God throughout all subsequent generations [רש״י].