It was narrated that Anas said:

"A man asked the Messenger of Allah ﷺ: 'O Messenger of Allah, how many prayers has Allah enjoined upon His slaves?' He said: 'Allah has enjoined upon His slaves (five) prayers.' He said: 'O Messenger of Allah, is there anything before them or after them?' He said: 'Allah has enjoined upon His salves (five) prayers.' The man swore that he would not do anything more or less than that. The Messenger of Allah ﷺ said: 'If he is speaking the truth he will most certainly enter Paradise.'"

أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا نُوحُ بْنُ قَيْسٍ، عَنْ خَالِدِ بْنِ قَيْسٍ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، قَالَ سَأَلَ رَجُلٌ رَسُولَ اللَّهِ ﷺ فَقَالَ يَا رَسُولَ اللَّهِ كَمِ افْتَرَضَ اللَّهُ عَزَّ وَجَلَّ عَلَى عِبَادِهِ مِنَ الصَّلَوَاتِ قَالَ " افْتَرَضَ اللَّهُ عَلَى عِبَادِهِ صَلَوَاتٍ خَمْسًا " . قَالَ يَا رَسُولَ اللَّهِ هَلْ قَبْلَهُنَّ أَوْ بَعْدَهُنَّ شَيْئًا قَالَ " افْتَرَضَ اللَّهُ عَلَى عِبَادِهِ صَلَوَاتٍ خَمْسًا " . فَحَلَفَ الرَّجُلُ لاَ يَزِيدُ عَلَيْهِ شَيْئًا وَلاَ يَنْقُصُ مِنْهُ شَيْئًا قَالَ رَسُولُ اللَّهِ ﷺ " إِنْ صَدَقَ لَيَدْخُلَنَّ الْجَنَّةَ " .