Muhammad said: His saying, {Completing [the favor] upon the one who did good}, means: a completion from Allah upon the doers of good; and this is the view held by Qatadah. (103b) {And as a completion} is in the accusative case, according to the sense of completion, and likewise {as a detailed explanation}, meaning: for the sake of completion and explanation.

Surah Al-An'am from verse (154) to verse (158).