Allah said,
(and We sent...) meaning, We sent
(in their footsteps) meaning the Prophets of the Children of Israel,
(`Isa, son of Maryam, confirming the Tawrah that had come before him,) meaning, he believed in it and ruled by it.
(and We gave him the Injil, in which was guidance and light) a guidance that directs to the truth and a light that removes the doubts and solves disputes,
(and confirmation of the Tawrah that had come before it,) meaning, he adhered to the Tawrah, except for the few instances that clarified the truth where the Children of Israel differed. Allah states in another Ayah that `Isa said to the Children of Israel,
(. ..and to make lawful to you part of what was forbidden to you.) So the scholars say that the Injil abrogated some of the rulings of the Tawrah. Allah's statement,
(a guidance and an admonition for those who have Taqwa.) means, We made the Injil guidance and an admonition that prohibits committing sins and errors, for those who have Taqwa of Allah and fear His warning and torment. Allah said next,
(Let the people of the Injil judge by what Allah has revealed therein.) meaning, so that He judges the people of the Injil by it in their time. Or, the Ayah means, so that they believe in all that is in it and adhere to all its commands, including the good news about the coming of Muhammad and the command to believe in and follow him when he is sent. Allah said in other Ayat,
(Say "O People of the Scripture! You have nothing (guidance) until you act according to the Tawrah, the Injil, and what has been sent down to you from your Lord.") and,
(Those who follow the Messenger, the Prophet who can neither read nor write whom they find written with them in the Tawrah...) until,
(...successful.) Here, Allah said,
(And whosoever does not judge by what Allah has revealed, such are the rebellious.) meaning, the rebellious and disobedient of Allah who prefer falsehood and abandon truth. We mentioned before that this Ayah was revealed about the Christians, and this is evident from the context of the Ayah.