What is the first corruption of the Children of Israel on Earth mentioned in Surat Al-Isra?

The exegetes differed regarding the identification of the first corruption by the Children of Israel. Some preferred that it was the killing of the Prophet of Allah, Zechariah, while others preferred that it was the killing of Isaiah. The inability to definitively choose between these opinions is due to the absence of clear evidence. Moreover, most of the narrations regarding the nature of this corruption are Isra'iliyyat (narrations from Jewish sources) which should not be unconditionally believed. Some meticulous scholars, such as Ibn Kathir, held that they should not even be mentioned. The meaning of the noble verse does not depend on knowing the exact nature of this corruption. One of the important principles in exegesis is that what the Sharia has left ambiguous, it is not necessary to pursue through Isra'iliyyat.