Indeed, what we contend to give you is comparatively, the easiest and plain.

It is a combination of particle and first personal plural pronoun
Only disagreements with this break down from work of Leads University UK. The is also separate it is a letter of interrogation meaning ?what?.
from root a verb ?contend to give? then there two attached pronouns meaning ?we? and ?you? in order
There is ?al? at the start explained. Then a definite noun with attached at the start. I am humbly disagreeing with all traditionalists including work at Leads neither that its root is nor it is as traditionally thought to be the case. If we accept the traditionalist view as correct. Then there is no rule in Arabic grammar to explain this construction. The is a particle of comparison and the root is meaning ?he made it easy and plain?.

Surah 108 2

Therefore, always follow it very closely; as it is from your Rabb and get to know it intelligently and thoroughly.

At start is the particle ?Fa? meaning ?then or therefore? followed by imperative of ii form of verb from root
?to follow closely? as being ii form adds meaning of ?intensity or repetition?.
At start is preposition ?lee? meaning ?for? at end personal pronoun ?ka? meaning you in middle ?rabb? explained before.
?Waw? at start conjunct particle, second person imperative from root with several meanings here due context picked up ?know intelligent or soundly?

Surah 108 3

For sure, it removes you away from him who severs all the bonds or relationships.

a particle explained above
a noun with attached personal pronoun ?ka? at end. Root is at measure of adding meaning of doer to root ?it or him removes away or aloof?.
Third person personal pronouns mean ?he?
The definite article ?al? followed by interrogative letter translated as ?who? and finally noun from root meaning ?he cut or severed ties or bond of relationships?.