Sunan Ibn Majah, Book 6, Hadith 1513 (In-Book) ⓘ
It was narrated from Ishaq bin ‘Abdullah bin Ja’far that his father said: “The Messenger of Allah said: ‘Urge your dying ones to say: “La ilaha illallahul-Halimul-Karim, Subhan-Allahi Rabbil-‘Arshil-‘Azim, Al-Hamdu Lillahi Rabbil-‘alamin (None has the right to be worshipped but Allah, the Forbearing, the Most Kind. Glory is to Allah, Lord of the magnificent Throne; praise is to Allah, the Lord of the worlds).’” They said: ‘O Messenger of Allah, what about those who are alive?’ He said: ‘Even better, even better.’”
حَدَّثَنَا مُحَمَّدُ بْنُ بَشَّارٍ، حَدَّثَنَا أَبُو عَامِرٍ، حَدَّثَنَا كَثِيرُ بْنُ زَيْدٍ، عَنْ إِسْحَاقَ بْنِ عَبْدِ اللَّهِ بْنِ جَعْفَرٍ، عَنْ أَبِيهِ، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ " لَقِّنُوا مَوْتَاكُمْ لاَ إِلَهَ إِلاَّ اللَّهُ الْحَلِيمُ الْكَرِيمُ سُبْحَانَ اللَّهِ رَبِّ الْعَرْشِ الْعَظِيمِ الْحَمْدُ لِلَّهِ رَبِّ الْعَالَمِينَ " . قَالُوا يَا رَسُولَ اللَّهِ كَيْفَ لِلأَحْيَاءِ قَالَ " أَجْوَدُ وَأَجْوَدُ " .
also referenced under: Hadith 1446 (Reference) & Volume 2, Book 6, Hadith 1446 (DarusSalam)