[The Abundance of Allah’s Signs for the Children of Israel]

The answer—and by Allah is success—is that the wisdom can appear by presenting a small introduction, which is:
Allah, the Exalted, by His knowledge and wisdom, chose the Children of Israel and selected them knowingly over the worlds. If they were His chosen elite among the worlds and the object of His selection—despite what they had of a nature of rebellion against Allah and against His prophets, and Allah, the Exalted, has related much of that in the Quran—then those besides them of humankind in that era would, without doubt, be worse than them, lower and more debased in rank, more deeply entrenched in rebellion, more intense in disbelief, and farther from Allah, from His religion, and from the call of His prophets; because Allah chooses none but the best, and selects none but the elite.
When you know this introduction that depicts the general condition of humankind in that era, and what they were upon of rebellion, depravity, and disbelief, then the elite of Allah among them and His best among them—the Children of Israel—were in need of what would straighten their crookedness, purify their harsh morals, and restrain their rebellion and obstinacy, until they reached the rank that qualifies them to be Allah’s proof and witnesses over the people.
So, the wisdom of the All-Knowing, the All-Wise required that He manifest for them the signs and follow up the clear proofs, to qualify them—as we mentioned—to carry Allah’s proofs and His clear evidences, and to be witnesses over the people.

Source: Min Thimār al-ʿIlm wa al-Ḥikmah vol.3