"In the morning I went to 'Ubadah bin As-Samit, and I met him while he was on his way to the Masjid. I told him what Abu Muhammad said, and 'Ubadah said: 'Abu Muhammad is wrong. I heard the Messenger of Allah (ﷺ) say: 'Five prayers are those that Allah has decreed for (His) slaves, whoever does them, and does not neglect any of them out of disregard toward them, will have a promise from Allah that He will admit him to Paradise. And whoever does not to them will have no such promise from Allah; if He wills he will punish him and if He wills He will admit him to Paradise.
Sunan an-Nasa'i Book 5, Hadith 14
← Previous Hadith "We were with the Messenger of Allah (ﷺ) and he said: 'Will you not pledge to the Messenger of Allah (ﷺ)?' And he repeated it three times. So we stretched forth our hands to give our pledge. We said: 'O Messenger of Allah, we are willing to give you our pledge, but on what?' He said: 'That you will worship Allah and not associate anything with him, and (offer) the five daily prayers.' And he said, very quietly: 'And you will not ask the people for anything.'"

Sunan an-Nasa'i Book 5, Hadith 13 Next Hadith → "Do you think that is there was a river by the door of any one of you, and he bathed in it five times each day, would there be any trace of dirt left on him?" They said: "No trace of dirt would be left on him." He said: "That is the likeness of the five daily prayers. By means of them Allah erases sins."

Sunan an-Nasa'i Book 5, Hadith 15