And what We have revealed to you -- O Muhلammad, of the Book, i.e., the Qur a0n,
(it is the (very) truth confirming that which was (revealed) before it.) means, of the previous books. It confirms them just as they bore witness to the coming of the Qur'an and that it would be sent down from the Lord of the worlds.
(Verily, Allah is indeed All-Aware and All-Seer of His servants.) means, He is All-Aware of them and knows who deserves to receive the blessing which He may give to him and not to others. the Prophets and the Messengers are favored above the rest of mankind, and some of the Prophets were given more than others and given higher status than others. The position given to Muhammad is higher than that of all the others, may the blessings and peace of Allah be upon them all.