He who forgets the prayer should say it when he remembers it, there is no explation for it, except this. Qatada said: (Allah says)" And observe prayer for remembrance of Me"  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ مَنْ نَسِيَ صَلاَةً فَلْيُصَلِّهَا إِذَا ذَكَرَهَا لاَ كَفَّارَةَ لَهَا إِلاَّ ذَلِكَ قَالَ قَتَادَةُ وَأَقِمِ الصَّلاَةَ لِذِكْرِي  

"Whoever forgets a prayer, let him pray it when he remembers it, for Allah says: and perform the Salah for My remembrance." [1] [1] Ta-Ha 20:14.  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ مَنْ نَسِيَ صَلاَةً فَلْيُصَلِّهَا إِذَا ذَكَرَهَا فَإِنَّ اللَّهَ تَعَالَى قَالَ { أَقِمِ الصَّلاَةَ لِذِكْرِي }  

"Whoever forgets a prayer, let him pray it when he remembers it, for Allah says: and perform the Salah for My remembrance." [1] [1] Ta-Ha 20:14. (Using translation from Nasāʾī 619)   

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ مَنْ نَسِيَ صَلَاةً أَوْ نَامَ عَنْهَا فَلْيُصَلِّهَا إِذَا ذَكَرَهَا إِنَّ اللَّهَ تَعَالَى يَقُولُ {وَأَقِمِ الصَّلَاةَ لِذِكْرِي} [طه 14]  

[Machine] That the Messenger of Allah, ﷺ , when he returned from the Battle of Khaybar, he mentioned the Hadith and in the end he said: "Whoever forgets a prayer, let him pray it when he remembers it; for indeed, Allah, the Most High, said: 'Establish prayer for My remembrance.' " Yunus said, "Ibn Shihab used to recite it in this manner."  

أَنَّ رَسُولَ اللهِ ﷺ حِينَ قَفَلَ مِنْ غَزْوَةِ خَيْبَرَ فَذَكَرَ الْحَدِيثَ وَفِي آخِرِهِ قَالَ مَنْ نَسِيَ صَلَاةً فَلْيُصَلِّهَا إِذَا ذَكَرَهَا؛ فَإِنَّ اللهَ تَعَالَى قَالَ أَقِمِ الصَّلَاةَ لِلذِّكْرَى قَالَ يُونُسُ وَكَانَ ابْنُ شِهَابٍ يَقْرَؤُهَا كَذَلِكَ  

"مَنْ نَسِيَ الصَّلاةَ فَلْيُصَلِهَا إِذَا ذَكرَهَا، فَإِنَّ اللهَ قَال: أَقِم الصَّلاةَ لِذِكْرِي".