Allah's Messenger (ﷺ) said: "O Abdullah bin Qais, should I not point you to one of the treasures of Paradise?" I said, "Yes, O Messenger of Allah." So he told me to say: Lā ḥawla wa lā quwwata 'illā billāh. Allah's Messenger (ﷺ) said: "O Abdullah bin Qais, should I not point you to one of the treasures of Paradise?" I said, "Yes, O Messenger of Allah." So he told me to say: There is no power and no might except by Allah. Reference: Al-Bukhari, cf. Al-Asqalani, Fathul-Bari 11/213, Muslim 4/2076.

Allah's Messenger (ﷺ) said: The most beloved words to Allah are four: Subḥānallāh Walḥamdu lillāh. Wa lā ilāha illallāh Wallāhu Akbar. Allah's Messenger (ﷺ) said: The most beloved words to Allah are four: Glorified is Allah, and The praise is for Allah, and There is none worthy of worship but Allah, and Allah is the Most Great. Reference: Muslim 3/1685.

A desert Arab came to Allah's Messenger (ﷺ) and said, "Teach me a word that I can say. " The Prophet (ﷺ) told him to say: Lā ilāha illallāh waḥdahu lā sharīka lah, Allāhu Akbaru kabīra, walḥamdu lillāhi kathīra, Subḥānallāhi Rabbil-`ālamīn, Lā ḥawla wa lā quwwata illā billāhi ‘l-`Azīzil-Hakīm. He said, "That is for my Lord, but what about me?" The Prophet (ﷺ) told him to say: Allāhummaghfir lī, warḥamnī, waḥdinī warzuqnī. A desert Arab came to Allah's Messenger (ﷺ) and said, "Teach me a word that I can say. " The Prophet (ﷺ) told him to say: There is none worthy of worship but Allah, Who has no partner, Allah is the Great, the Most Great, and praise is to Allah in abundance, glory is to Allah, Lord of the worlds. There is no power and no might but by Allah the Mighty, the Wise. He said, "That is for my Lord, but what about me?" The Prophet (ﷺ) told him to say: O Allah forgive me, and have mercy on me and guide me, and provide for me. Reference: Muslim 4/2072, Abu Dawud reports the same Hadith with the addition: and when the Arab left, the Prophet (ﷺ) said: "He has filled his hands with goodness." 1/220.

Whenever anyone accepted Islam, the Prophet (ﷺ) used to teach him how to pray then he would instruct him to invoke Allah with the following words: Allāhummaghfir lī, warḥamnī, waḥdinī, wa `āfinī warzuqnī. Whenever anyone accepted Islam, the Prophet (ﷺ) used to teach him how to pray then he would instruct him to invoke Allah with the following words: O Allah forgive me, and have mercy on me and guide me and give me good health and provide for me. Reference: Muslim 4/2073, and in one of Muslim's reports there is the addition: 'For these words combine this world and the next.'

The most excellent invocation is: Alḥamdulillāh and the most excellent words of remembrance are: Lā ilāha illallāh. The most excellent invocation is: Praise is for Allah. and the most excellent words of remembrance are: There is none worthy of worship but Allah. Reference: At-Tirmidhi 5/462, Ibn Majah 2/1249, and Al-Hakim who graded it authentic and Ath-Tbahabi agreed 1/503. See Al-Albani, Sahihul-Jami' As-Saghir 1/362.

The good deeds which endure are: Subḥānallāh. Walḥamdu lillāh. Wa lā ilāha illallāh Wallāhu Akbar Wa lā ḥawla wa lā quwwata illā billāh. The good deeds which endure are: Glorified is Allah, and The praise is for Allah, and There is none worthy of worship but Allah, and Allah is the Most Great, and There is no power and no might except by Allah. Reference: Ahmad (no. 513) (Ahmad Shakir, ed.) and its chain of narration is authentic. See Majma'uz-Zawa'id 1/297. Ibn Hajar mentions it in Bulughul-Maram saying that Ibn Hibban and Al-Hakim considered it authentic.

Abdullah bin 'Amr (RA) said: "I saw the Prophet (ﷺ) counting the glorification of his Lord on his right hand." Reference: Abu Dawud with a different wording 2/81, and At-Tirmidhi 5/521. See also Al-Albani, Sahihul-Jami'As-Saghir 4/271 (no. 4865).

When night falls, restrain your children (from going out) because at such time the devils spread about. After a period of time has passed, let them be. Shut your doors and mention Allah’s name, for verily the devil does not open a shut door, tie up your water-skins and mention Allah’s name, cover your vessels with anything and mention Allah’s name and put out your lamps. Reference: Al-Bukhari with Al-Fath 10/88 and Muslim 3/1595.