When should we say “Laa hawla wa laa quwwata illa Billaah”?

Pls. let me know the :
(1) meaning with
(2) brief commentary of the sentence, 'LAL HAWLA WALA KUWATAH ILLAH BILLAH HU WAL ALIEL AZIM".
(3) And, when the same is used.

Praise be to Allaah.

The meaning of this phrase (there is no power and no strength except with Allaah) is a person’s admission that he is unable to do anything without the help and support of Allaah. No matter how great his power, energy and strength may become, a person still cannot do anything without the help of Allaah Who is Above all of His creation, the Most Great, compared to Whom nothing else is great. Every strong person is weak when compared with Allaah. Every great person is insignificant and weak when compared with His Might.

This sentence is uttered when some serious matter befalls a person that he cannot cope with, or there is something that it is very difficult for him to deal with.

Shaykh Sa’d al-Humayd.

Among the occasions on which this phrase is uttered are the following:

– When turning over at night:

It was reported that ‘Ubaadah ibn al-Saamit said: “The Messenger of Allaah (peace and blessings of Allaah be upon him) said: ‘Whoever turns over at night and says Laa ilaaha ill-Allaah wahdahu laa shareeka lah, lahu’l-mulk wa lahu’l-hamd wa huwa ‘ala kulli shay’in qadeer. Al-hamdu-lillaah wa subhaan-Allaah wa laa ilaaha ill-Allaah wa Allaahu akbar, wa laa hawla wa laa quwwata illa Billaah (There is no god but Allaah Alone, with no partner or associate. To Him belongs praise and His is the sovereignty, and He is Able to do all things. Praise be to Allaah, glory be to Allaah, there is no god but Allaah and Allaah is Most Great. There is no power and no strength except with Allaah), then he says, Allaahumma aghfir li (O Allaah, forgive me), or he makes du’aa’, his prayer will be granted. If he does wudoo’ and prays, his salaah will be accepted.” (Narrated by al-Bukhaari, 1086)

– When the muezzin says “Hayya ‘ala’l-salaah (come to prayer)” or “Hayya ‘ala’l-falaah (come to success)”

It was narrated from Hafs ibn ‘Aasim ibn ‘Umar ibn al-Khattaab, from his father, that his grandfather ‘Umar ibn al-Khattaab said: “The Messenger of Allaah (peace and blessings of Allaah be upon him) said: ‘When the muezzin says “Allaahu akbar, Allaahu akbar (Allaah is Most Great),” and one of you says, “Allaahu akbar, Allaahu akbar”; then he says, “Ashhadu an laa ilaaha illa Allaah (I bear witness that there is no god except Allaah” and you say “Ashhadu an laa ilaaha illa Allaah”; then he says, “Ashhadu anna Muhammadan Rasool Allaah (I bear witness that Muhammad is the Messenger of Allaah” and you say, “Ashhadu anna Muhammadan Rasool Allaah”; then he says, “Hayya ‘ala’l-salaah (come to prayer)” and you say, “Laa hawla wa laa quwwata illa Billaah”; then he says, “Hayya ‘ala’l-falaah (come to success)” and you say, “Laa hawla wa laa quwwata illa Billaah”; then he says “Allaahu akbar, Allaahu akbar,” and you say, “Allaahu akbar, Allaahu akbar”; then he says “Laa ilaaha illa Allaah” and you say, “Laa ilaaha illa Allaah” – if he says that from the heart, he will enter Paradise.’” (Narrated by Muslim in his Saheeh, 578, and by Abu Dawood in his Sunan, 443)

– When leaving one's house

It was narrated that Anas ibn Maalik said: “The Messenger of Allaah (peace and blessings of Allaah be upon him) said: ‘Whoever says – i.e., when he is leaving his house – “Bismillaah, tawwakaltu ‘ala Allaah, laa hawla wa laa quwwata illa Billaah (In the name of Allaah, I put my trust in Allaah, and there is no power and no strength except with Allaah),” it will be said to him, “You are taken care of and protected,” and the Shaytaan will leave him alone.’” (Narrated by al-Tirmidhi in his Sunan, 3348. Abu ‘Eesa said, this is a hasan saheeh ghareeb hadeeth which we only know through this isnaad. See Saheeh al-Jaami’ by al-Albaani, 6419. It was also narrated by Abu Dawood in his Sunan (4431), where he adds: “And another shaytaan says to him, ‘What can you do with a man who has been guided, taken care of and protected?’”)

– After praying

It was narrated that Abu’l-Zubayr said: “Ibn al-Zubayr used to say immediately after every prayer, when he had said the salaam, ‘Laa ilaaha ill-Allaah wahdahu laa shareeka lah, lahu’l-mulk wa lahu’l-hamd wa huwa ‘ala kulli shay’in qadeer. Laa hawla wa laa quwwata illa Billaah wa laa na’budu illaa iyyaah. Lahu’l-ni’mah wa lahu’l-fadl wa lahu’l-thanaa’ al-hasan. Laa ilaaha ill-Allaah mukhliseena lahu’l-deena wa law kariha’l-kaafiroon (There is no god but Allaah Alone, with no partner or associate His is the sovereignty and to Him be praise, and He is Able to do all things. There is no power and no strength except with Allaah, and we worship none but Him. From Him (alone) come all blessings and favours, and all good praise is due to Him. There is no god but Allaah and we make our worship purely for Him (alone) however much the disbelievers may hate that).’ He said: ‘The Messenger of Allaah (peace and blessings of Allaah be upon him) used to say these words immediately after every prayer.’” (Narrated by Muslim in his Saheeh, 935)