Certainly was Allah pleased with the believers when they pledged allegiance to (48:18)

Almuntakhab Fi Tafsir Alquran Alkarim

How well pleased has Allah been with the believers whose hearts reflect the image of virtues as they were making the vow to you under the tree to devote themselves to Allah and to serve His purpose; He knew well what they had at heart and that they made the vow with the deepest feeling. Therefore He inspired them with peace and tranquility and decreed to reward them with a victory that is quite near

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(48:18) Allah was much pleased with the believers when they swore fealty to you under the tree. *32 He knew what was in their hearts. So He bestowed inner peace upon them *33 and rewarded them with a victory near at hand

Certainly was Allah pleased with the believers when they pledged allegiance to meaning

*32) Here again the pledge taken from the Companions at Hudaibiyah has been mentioned. This is called Bai 'at Ridwan. for AIIah in this verse has given the good news that he became well pleased with those who on this dangerous occasion did not show the least hesitation in offering their lives for the cause of Islam and gave an express proof of their being true in their faith by taking the pledge on the hand of the Holy Prophet. The Muslims at this time were equipped only with a sword each. numbered only 1,400, were unprepared for warfare, but were donning the pilgrim garments, were 25 miles away from their military headquarters (Madinah), while the enemy's stronghold (Makkah) wherefrom it could get any kind of help was just 13 miles off. Had these people been lacking in their sincerity fo AIIah and His Messenger and His Religion in any degree, they would have abandoned the Messenger on this extremely dangerous occasion, and Islam would have been vanquished for ever. Apart from their own sincerity there was no external pressure under which they might have been compelled to take the pledge. Their becoming ready at that time to fight in the cause of Allah's Religion regardless of the dangers, is a clear proof that they were true and sincere in their Faith and loyal to th ' cause of AIIah and His Messenger in the highest degree. That is why AIIah honoured them with this certificate of His good pleasure. Now it some one becomes angry with them after they have been honoured with this certificate of Allah's good pleasure, or slanders and vilifies them, his enmity is with Allah, not with them. Those who say that at that time when Allah honoured them with this certificate of His good pleasure, they were sincere, but afterwards they became disloyal to AIlah and His Messenger, perhaps harbour a mistrust about Allah that while sending down this verse He was unaware of their future; therefore, He awarded them this warrant only in view of their state at that time, and probably due to the same unawareness inscribed this verse in His Holy Book as well so that afterwards also, when those people have turned disloyal, the world should continue reading this verse about them and praising the knowledge of the unseen of that AIlah Who, God forbid, had granted these faithless and disloyal people the warrant of His good pleasure. About the Tree under which this pledge was taken Ibn `Umar's slave Hadrat Nafi's tradition has generally spread saying that the people had started visiting it and offering Prayers by it, so that when Hadrat 'Umar came to know of it, he rebuked and warned the people and ordered it to be cut down . ( Tabaqat Ibn Sa'd, vol. II, p. l00). But there are several other traditions which contradict it. A tradition from Hadrat Nafi' himself has been reported in Tabaqat of Ibn S`ad to the effect that many years after the Bai at Ridwan the Companions looked for the Tree but they could not recognize it and differed as to which tree it was. (p. 106). The second tradition has been reported in Bukhari, Muslim, and Tabaqat on the authority of Hadrat Said bin al-Musayyab. He says that his father was one of those who had participated in the Bai `at Ridwan. He told him that when they had gone for 'Umrah al-Qada the following year, they had forgotten the Tree, and they could not locate it even after looking for it. The third tradition is from lbn Jarir. He says that when Hadrat `Umar during his caliphate passed by Hudaibiyah, he enquired about the Tree under which the pledge had been sworn. Someone pointed to one tree and another one to another tree. At this Hadrat `Umar told the people to forget it as there was no real need to bother about it.
*33) Here, sakinat means that state of the heart on whose strength a man throws himself into dangers with complete calm and peace of mind for the sake of a great objective and resolves without fear and consternation to undertake it regardless of the consequences.
 

Certainly was Allah pleased with the believers when they pledged allegiance to meaning in Urdu

اللہ مومنوں سے خوش ہو گیا جب وہ درخت کے نیچے تم سے بیعت کر رہے تھے ان کے دلوں کا حال اُس کو معلوم تھا، اس لیے اس نے ان پر سکینت نازل فرمائی، ان کو انعام میں قریبی فتح بخشی