This is the declaration from Lord Allah and His Messenger to free all the agreements you had with the Mushriks.
Hudayybiya Treaty was made between Mecca Mushriks and believers in the Hijra 6th year as explained in verse 48: 20. But the Mecca Mushriks were breaching the conditions of the Treaty. Thus, on Hijra 8th, Meccan Triumph has happened and Mecca came under the control of believers. On Hijra 9th, the believers performed pilgrimage under the leadership of Aboobacker in the Islamic way while Mushriks performed it in their traditional way. In that pilgrimage verses, 1-40 of this Surath was explained to the people. And in addition to it, four conditions were declared: (1) Nobody will enter the Paradise without becoming believer (2) Mushriks who associate in the Dominion of Lord Allah shouldn’t participate in the pilgrimage after this year. (3) Encircling of Ka’bah in the nude is prohibited. (4) Those from the Mushriks who agree with Messenger, if they are not breaching it, the agreements will exist till their terms.
The Farewell Pilgrimage happened in Hijra 10th was under the leadership of Messenger Muhammad and it was completed in the Islamic way. Thus, on that day, the way of life of Lord from Adam to Last Day—Islam—was fulfilled by revealing the part of verse 5: 3.
As explained in verse 3: 7, after 30 years of Messenger’s departure the Book reading people are in three groups. Among them 1 in 1000—believer—who follows the dos and don’ts of Lord’s Book Adhikr are only be in the Straightpath as explained in verses 1: 5; 2: 256; 3: 101 and 4: 174-175. The other two groups are the Fajir and Kafir. They are the Fujjar whose ledger is in Sijjeen of Hell as told in verse 83: 7. When the believer read verse 1: 4, he should pray by soul not to include among the wrath happened hypocrites and their strayed followers mentioned in verse 1: 7. See explanations 7: 127, 137 and 168.