All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
After researching the matter, we have not come across any Hadeeth stating that one should say La Hawla wa laa quwwata illa billaahi al’aliyy Al-‘Atheem (There is no might nor power except with Allaah, Most High, the Great) after reciting Aayatul-Kursi. [Quran 2:255]
Shaykh ‘Abdul-Azeez ibn Baaz said in Tuhfatul Akhyaar: "After saying Salaam in the five obligatory prayers, it is confirmed that the Prophet when he would say Salaam when finishing an obligatory prayer, he would say: Astaghfiru Allaah (I ask Allaah for forgiveness) three times; Allaahumma anta as-salaam wa minka as-salaam tabaarakta ya thal jalaali wal Ikraam (O Allaah, You are Peace and from You is peace; blessed are You, O One of Majesty and Honor), La ilaaha illaa Allaah wahdahu laa shareeka lahu, lahul-mulku walahul-hamdu, wahuwa ‘ala kulli shay’in qadeer, allahumma la maani’a lima a’tayta, wala mu’tiya lima mana’ta, wala yanfa’u thal-jaddi mink al-jadd (None has the right to be worshipped except Allaah, alone, without partner; to Him belongs all sovereignty and praise and He is over all things able. O Allaah, none can prevent what You give and none can give what You prevent, and no majesty can avail; from You is all majesty), La ilaaha illaa Allaah wahdahu laa shareeka lahu, lahul-mulku walahul-hamdu, wahuwa ‘ala kulli shay’in qadeer, la hawla wala quwwata illa billaah, la ilaaha illa Allaah, wala na’budu illa iyyah, lahu an-ni’matu walahul-fadhlu wa lahu aththanaa’ul hasan, laa ilaaha illa Allaahu mukhliseena lahud-deena walaw karihal-kaafiroon (None has the right to be worshipped except Allaah, alone, without partner, to Him belongs all sovereignty and praise and He is over all things able. There is no might nor power except with Allaah, none has the right to be worshipped except Allaah and we worship none except Him. For Him is all favor, grace, and glorious praise. None has the right to be worshipped except Allaah and we are sincere in faith and devotion to Him even if the disbelievers detest it. Then, he would say: Subhaana Allaah (thirty-three times), Alhamdu lillaah (thirty-three times), Allaahu Akbar (thirty-three times) and then: La ilaaha illa Allaah wahdahu laa shareeka lahu, lahu Al-mulku walahu Al-hamdu, wa huwwa ‘ala kulli shay’in qadeer (None has the right to be worshipped except Allaah, alone, without partner, to Him belongs all sovereignty and praise and He is over all things able). Then he would recite Aayatul Kursi [Quran 2:255], Soorah 112, Soorah 113, and Soorah 114, after each obligatory prayer…” [End of quote]
It was also mentioned by some scholars as one of the Athkaar to be recited when going out of the house. For example, Minah Al-Jaleel Sharh Mukhtasar Khaleel (a
Maaliki book) reads: “…When entering or leaving [the house]. One should add when entering: “O Allaah, I ask you for the best exit and the best entry,” and Soorah Al-Ikhlaas (Chapter 112), Al-Faatihah (Chapter 1), Aayatul Kursi (Quran 2:255). When leaving, one should add: "Tawakkaltu ‘ala Allaah, wala hawla wala quwwata illa billaah al-'aliyy al-'atheem; bismi Allaahi ‘ala nafsi wa ‘ala deeni wa ‘ala awlaadi; allaahumma radhdhini bima qadhayta li wa baarik li feema razaqtani hatta laa uhibba ta’jeela maa akhkharta wa la ta’kheera ma ‘ajjalta Allaahumma inni a’oothu bika an adhilla aw udhall, aw azilla aw uzall, aw athlima aw uthlam, aw abghi aw yubgha ‘alayya; ’azza jaaruka wa jalla thanaa’uka (I place my trust in Allaah, and there is neither might nor power except with Allaah, The Most High, The Supreme. In the name of Allaah on myself, on my religion and on my children. O Allaah make me content with what You have ordained for me, and bless me in what you have written for me so that I do not love to hasten what You have delayed nor to delay what you have hastened; O Allaah, I take refuge in You lest I should stray or be led astray, or slip or made to slip, or wrong or be wronged, or oppress or be oppressed; indeed, honored is Your company and great is Your praise); and then reciting Aayatul Kursi.” [End of quote]
The two Athkaar were also mentioned together in some Dha’eef (weak) Ahaadeeth such as those mentioned by Ibn Hajar in Amaali Al-Athkaar, about the goodness of the Tasbeeh prayer. He said: “‘Ali related another Hadeeth that greatly contrasts what was mentioned above. Abu Nu’aym reported it in his book, Qurbaan Al-Muttaqeen, from two chains of narrators, one continuous and the other discontinuous. He said: “The Prophet said: “Whoever performs Dhuha prayer four Rak’ahs on Friday, once in his lifetime, reciting Al-Faatihah, Soorah Al-Kaafiroon [Quran 109], Soorahs 112, 113, and 114, and Aayatul Kursi, in each Rak’ah 10 times, and when he finishes Tashahhud, he says forty times 'Subhaan Allaah, Alhamdulillaah, Allaahu Akbar and Laa hawla wala kuwwata illa billaah', Allaah will repel from him the evil of those in the heavens and the evil of those on earth…” He mentioned a lengthy Hadeeth, about one page long. Abu Nu’aym then said after assessing the Hadeeth: 'It contains contradicted elements and apparent traces of fabrication.” [End quote]
Allaah Knows best.