The Almighty says: "So stand firm (in the straight path) as you are commanded." What is the story behind this verse?

In interpretation of Allah Almighty's saying: "So remain steadfast as you have been commanded – you and those who have turned back with you – and do not transgress. Indeed, He is Seeing of what you do" (Hud: 112), Allah commands His Prophet Muhammad and the believers to remain firm upon Allah's command and the religion with which He sent them, and to be steadfast upon the correct laws and sound beliefs without deviation or transgression of limits. This verse comes after mentioning the states of the fortunate and the wretched, and the polytheists and those who differed about the Scripture, to guide them towards steadfastness and avoiding transgression of limits. The Prophet, peace and blessings be upon him, was asked about a matter in Islam about which no one after him would need to ask, and he said: "Say, 'I have believed in Allah,' and then remain steadfast."