Therefore...

Therefore, Allah -azwj , although in clear Knowledge, Praised those who sincere in their pledge without specifically excluding the insincere ones – that was to be left for a later time when their actions led them to their separation from the praised group of Momineen.

After Rasool-Allah -saww , the differing of Muslims started and reached to the point where some of those who pledged allegiance under the tree, were fighting against each other, thereby, were responsible for killings of thousands of Muslims in the battle fields (i.e., Jamal, Siffeen).

Some Sunni Muslims, may here try to justify the differing of the ‘Muslims under the tree’, by quote a Hadith, in which allegedly Rasool-Allah -saww said: says: ‘ Difference of opinion among my Ummah is a mercy ’, but it is against the Words of Allah -azwj in the Holy Quran where Allah -azwj Says: “And mankind was not but one community (united in religion), but (then) they differed. …” [Yunus 10: 19] and there are many other Verses Forbidding the differing (e.g., 6:159, 3:103).

Surely your Lord will Judge between them on the Day of Judgement with regards to what they were differing in [10:93]. The differing on religion means some of them were on the right path whereas the others were on the wrong path, so Allah -azwj will Decide regarding them on the day of Judgement, to whom to reward and to whom to punish.

Also Allah -azwj has praised Bani Israel as well as Reprimanded them (see for example Appendix), as both believers and unbelievers were present in both places (of Praise and Reprimand), but Allah -azwj Praised the Bani Israel nation while intending for the believers within them and rebuking the unbelievers/hypocrites of the Bani Israel but without distinguishing believers.

When Allah -azwj Commanded Angels to Bow Down to Adam, Iblis who was made out of fire and was living among angels was also included in those who were Commanded by Allah -azwj .