The Quran

فَاصبِر إِنَّ وَعدَ اللَّهِ حَقٌّ وَاستَغفِر لِذَنبِكَ وَسَبِّح بِحَمدِ رَبِّكَ بِالعَشِيِّ وَالإِبكارِ

Ali Unal

So be patient (O Messenger, with whatever they do), for surely God’s promise (that He always helps His Messengers and the believers) is true; and ask forgiveness for your sins;¹ and glorify your Lord with His praise² in the afternoon and morning hours.

Infallibility is an indispensable attribute of Prophethood. So all the Prophets are infallible in the sense that they do not sin or disobey God’s orders. Here, God reminds the believers of an important fact to which we must be attentive on the way to Him. What falls on those who believe in God, and who endeavor to attain the level of ordering their life according to the rules that are established in His Book, is to be patient, ask for His forgiveness for their sins, and as will be stated in the verse, to be occupied with His glorification and praise.
On the meaning of glorifying God and praising Him, see 35: 29, note 11.