(… قُلْ آمَنَّا بِاللَّهِ ) (Say, “We have believed …): Normally (in Arabic) the verb ‘say’ must be followed by a singular (I have believed). In the Holy Quran, however, every single word calls its meaning, as Holy Quran is addressed to the Prophet (saws), who, in turn, addresses a nation that has to follow. Thus, it is (Say, “We have believed} not (Say, “I have believed”).
(… وَمَا أُنزِلَ عَلَيْنَا وَمَا أُنزِلَ عَلَىٰ إِبْرَاهِيمَ وَإِسْمَاعِيلَ وَإِسْحَاقَ وَيَعْقُوبَ وَالْأَسْبَاطِ وَمَا أُوتِيَ مُوسَىٰ وَعِيسَىٰ وَالنَّبِيُّونَ مِن رَّبِّهِمْ …) (…And in what was revealed to us and what was revealed to Abraham, Ishmael, Isaac, Jacob, and the Descendants, and in what was given to Moses and Jesus and the prophets from their Lord.…): Just consider the sequence (unity) of the Divine Messages here.
‘The Descendants’ are the breeds of the Family of Israel, descendants of Israel’s -Jacob’s- twelve children.
( وَنَحْنُ لَهُ مُسْلِمُونَ … ) (…And we are Muslims [submitting] to Him.”): We are all subject to the Almighty