Curses were pronounced on those among the Children of Israel who rejected Faith, by the tongue of David and of Jesus the son of Mary: because they disobeyed and persisted in excesses.
Those among the Children of Israel who disbelieved were cursed by the tongue of Dawud (David) and ‘Iesa (Jesus), son of Maryam (Mary). That was because they disobeyed (Allah and the Messengers) and were ever transgressing beyond bounds. (Verse 78)
They used not to forbid one another from the Munkar (wrong, evildoing, sins, polytheism, disbelief, etc.) which they committed. Vile indeed was what they used to do. (Verse 79)
The following excerpt is taken from “In the Shade of the Quran” Volume 4 pg. 173:
When we remember that it was Jesus and David who cursed the Children of Israel, we realise that theirs is a long history of unbelief, disobedience and rejection of the truth. Prophets who were sent to guide and save them were the ones who eventually condemned them so that they might not be guided to the truth. God answered their prayers and destined the Israelites to a perpetual curse.
The unbelievers among the Children of Israel were the ones who distorted their revealed Scriptures and refused to abide by the rulings of the Divine Code, as we are told in several Qur’ānic sūrahs. They violated their covenant with God in which they pledged themselves to support and follow every messenger He sent: “That was because they rebelled and persisted in their transgression.” (Verse 78)
Jewish history is full of examples of such rebellion and aggression. These were not mere individual actions in the Jewish community. Indeed, they were so frequent they became characteristic of the whole community, and even those who did not perpetrate such crimes either turned a blind eye to them or did not speak out against them: “They would never restrain one another from wrongdoing. Vile indeed were the things they did.” (Verse 79)
According to “Tafhim ul Quran” note 102, under the commentary of the above verse:
“The corruption of any nation begins with that of a few individuals. If the collective conscience of that nation is alive, the pressure of public opinion keeps those persons in check and prevents the nation as a whole from becoming corrupted. But if instead of censuring such individuals, the nation leaves them free to behave corruptly, the corruption originally confined to a few continues to spread till it engulfs the whole nation. It was this which ultimately caused the degeneration of Israel. (For the curse against Israel in the words of David and Jesus see Psalms 10, 50 and Matthew 23.)”
In the Shade of the Quran further writes:
“As the Qur’ān depicts this phenomenon of Israelite society, condemning it and showing it in a bad light, it wants for the Muslim community a solid structure which repels every aspect of rebellion and transgression. It wants the Muslim community to solidly defend the truth and to be sensitive to any aggression against it. It wants those who advocate the implementation of faith to discharge their responsibility by standing firm against evil, corruption, tyranny and transgression. The Muslims should pay no heed to anyone who blames them for their attitude. They maintain their opposition to evil whether it is practised by powerful rulers, influential men of wealth, evil people with physical power or the masses swayed by vain desires. God’s system remains the true system and those who deviate from it are all alike, be they people of high or low position. Islam strongly emphasises the need to fulfil God’s trust, and threatens a common punishment to the whole community if it allows evil to spread within it. The responsibility is shared by every individual and by the community as a whole.” (pg. 173-174)
Maududi, Abul Ala (2010). Tafhim ul Quran. (note 102). https://www.englishtafsir.com/Quran/6/index.html#sdfootnote27sym
Qutb. In the Shade of the Quran. (Vol. 4 p. 173-174) https://archive.org/details/Volume1Surah12