Fasabbih bihamdi rabbika wastaghfirhu innahu kana tawwaba (surah Nasr: 3)

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

(110:3) then extol the praise *3 of your Lord and pray to Him for forgiveness. *4 For He indeed is ever disposed to accept repentance.

Fa sab bih bihamdi rabbika was taghfir, innahu kaana tawwaaba

*3) Hamd implies praising and hallowing Allah Almighty as well as thanking and paying obeisance to Him; tasbih means to regard Allah as pure and free from every blemish and weakness. The Holy Prophet was enjoined to do hamd and tasbih of Allah when he witnessed this manifestation of His power. Here, hamd means that in respect of his great success he should never entertain even a tinge of the idea that it was the result of any excellence of his own, but he should attribute it to Allah's favour and mercy, thank Him alone for it, and acknowledge with the heart and tongue that praise and gratitude for the victory and success belonged to Him alone. And tasbih means that he should regard Allah as pure and free from the limitation that exaltation of his Word stood in need of his effort and endeavour, or was dependent on it. On the contrary, his heart should be filled with the faith that the success of his effort and struggle was dependent upon Allah's support and succour. He could take this service from any of His servants He pleased. and it was His favour that He had taken it from him, and made His religion meet success through him. Besides, there is an aspect of wonder also in pronouncing the tasbih, i.e. Subhan Allah. When a wonderful incident takes place, one exclaims subhan A/lah, thereby implying that only by Allah's power such a wonderful thing had happened; otherwise no power of the world could have caused it to happen.
*4) "Pray for His forgiveness": "Pray to your Lord to overlook; and pardon whatever error or weakness you might have shown inadvertently in the performance of the service that He had entrusted to you," This is the etiquette that Islam has taught to man. A man might have performed the highest possible service to Allah's Religion, might have offered countless sacrifices in its cause, and might have exerted himself extremely hard in carrying out the rites of His worship, yet he should never entertain the thought that he has fulfilled the right his Lord had on him wholly. Rather he should always think that he has not been able to fulfil what was required of him, and he should implore Allah, saying: "Lord, overlook and forgive whatever weakness I might have shown in rendering Your right, and accept the little service that I have been able to perform." When such an etiquette was taught to the Holy Messenger (upon whom be peace), none in the world conceivably has toiled and struggled so hard in the cause of Allah as he did, how can another person regard his work as superb and be involved in the misunderstanding that he has fulfilled the right Allah had imposed on him? Allah's right, in fact, is so supreme that no creature can ever fulfil and render it truly and fully.
Allah in this command has taught Muslims an eternal lesson: "Do not regard any of your worship, devotion or religious service as something superb; even if you have expended your entire life in the cause of Allah, you should always think that you could not do all that was required of you by your Lord. Likewise, when you attain some victory, you should not regard it as a result of some excellence in yourselves but as a result of only Allah's bounty and favour. Then bowing humbly before your Lord, you should praise and glorify Him, and should repent and beg for His forgiveness instead of boasting and bragging of your success and victory."