Ubaydullah bin Abdullah bin Utba reported,
Ibn Abbas said to me, "Do you know the last surah of the Quran to be revealed all at once?"I replied, "Yes, 'When the help of Allah comes and the victory' [Nasr 110:1]."He said, "You have spoken the truth."
Azami 13793
Sahihعن عبيد الله بن عبد الله بن عتبة قال
قال لي ابن عباس: تعلم آخر سورة نزلت من القرآن، نزلت جميعا؟ قلت: نعم، {إذا جاء نصر الله والفتح} قال: صدقت.
Muslim narrated it in the tafsir (2024) through several routes from Jafar bin Awn, who said, Abu Umays informed us, from Abdul-Majid bin Suhayl, from Ubaydullah bin Abdullah bin Utba, who said, then he mentioned it.His saying, "So glorify the praise of your Lord and seek His forgiveness, for He is ever accepting of repentance" [Nasr 110:3], contains an urging for everyone who senses the nearness of his appointed time, whether through illness or old age, to increase his seeking of forgiveness. This is why the Messenger of Allah ﷺ used to interpret the Quran in this way, frequently saying in his bowing and prostration, "Glory be to You, O Allah, and praise be to You, O Allah, forgive me," as Ayesha 
mentioned.His saying, "for He is ever accepting of repentance" [Nasr 110:3], is an intensified form of the expression "He accepted his repentance."