Al-Ma'idah: 71
"And they thought there would be no..."
If you ask: How does the verb of "thinking" (ḥusbān) enter upon "that" (an) which is for verification?
I say: Their thinking was treated—due to its strength in their hearts—as if it were certain knowledge.
If you ask: Where are the two objects of "thought" (ḥasiba)?
I say: The clause contained within the connection of "that" (an), along with its predicate and subject, occupies the place of the two objects. The meaning is: The Children of Israel thought that no trial—meaning affliction and punishment in this world and the Hereafter—would befall them from Allah.
"And they became blind"
To the religion.
"And they became deaf"
When they worshipped the calf, then they repented from the worship of the calf.
"Then Allah turned to them in forgiveness; then many of them became blind and deaf"
This is a second occurrence, referring to their demand for the impossible and irrational regarding the attributes of Allah, which is [the demand for] vision.
It is also recited as ‘ummū wa-ṣammū (with the ḍamma), based on the estimation that "Allah blinded them and deafened them." That is, He cast them and struck them with blindness and deafness, just as one says nazaktuhu (I speared him) when you strike him with a spear, or rakabtuhu (I kneeled him) when you strike him with your knee.
"Many of them"
This is a substitute (badal) for the pronoun [in the verb], or it follows the linguistic usage of "the fleas ate me" (akalūnī al-barāghīth), or it is the predicate of an omitted subject, meaning: "Those are many of them."