Suhail narrates that his teacher Abu Salih would command them, that when one of them intends to sleep he should lay on his right side and then he should say:

O Allah! The Lord of the Heavens, the Lord of the earth, the Lord of the great throne, our Lord and the Lord of everything, the one who splits the grain and the date stone, the one who sent down the Tawrah, Injeel and Quran. I seek Your refuge from the evil of everything in Your control. O Allah! You are the first and there is nothing before you, You are the last and nothing is after You, You are the apparent and there is nothing more apparent than You, You are the hidden (from the creation’s sight) and there is nothing more hidden than You. Settle our debts and spare us from poverty.

Abu Salih would narrate this from Abu Hurairah from the Prophet peace be upon him.

عَنْ سُهَيْلٍ قَالَ كَانَ أَبُو صَالِحٍ يَأْمُرُنَا إِذَا أَرَادَ أَحَدُنَا أَنْ يَنَامَ أَنْ يَضْطَجِعَ عَلَى شِقِّهِ الأَيْمَنِ ثُمَّ يَقُولُ

اللَّهُمَّ رَبَّ السَّمَوَاتِ وَرَبَّ الأَرْضِ وَرَبَّ الْعَرْشِ الْعَظِيمِ رَبَّنَا وَرَبَّ كُلِّ شَىْءٍ فَالِقَ الْحَبِّ وَالنَّوَى وَمُنْزِلَ التَّوْرَاةِ وَالإِنْجِيلِ وَالْفُرْقَانِ أَعُوذُ بِكَ مِنْ شَرِّ كُلِّ شَىْءٍ أَنْتَ آخِذٌ بِنَاصِيَتِهِ اللَّهُمَّ أَنْتَ الأَوَّلُ فَلَيْسَ قَبْلَكَ شَىْءٌ وَأَنْتَ الآخِرُ فَلَيْسَ بَعْدَكَ شَىْءٌ وَأَنْتَ الظَّاهِرُ فَلَيْسَ فَوْقَكَ شَىْءٌ وَأَنْتَ الْبَاطِنُ فَلَيْسَ دُونَكَ شَىْءٌ اقْضِ عَنَّا الدَّيْنَ وَأَغْنِنَا مِنَ الْفَقْرِ

وَكَانَ يَرْوِى ذَلِكَ عَنْ أَبِى هُرَيْرَةَ عَنِ النَّبِىِّ -صلى الله عليه وسلم.

(رواه أبو يعلى في مسنده، مسند معاذ بن أنس، ح/١٤٨٨)