This format of sending blessings upon the Prophet (blessings and peace of Allah be upon him) is made up; it was not narrated in the Sunnah or reports.
Rather it is mentioned by the author of Nuzhat al-Majaalis wa Muntakhab an-Nafaa’is (p. 284); and by the literary historian ‘Abd ar-Rahmaan ibn ‘Abd as-Salaam as-Safoori (d. 894 AH); and by Shaykh ‘Umar ibn ‘Ali ibn Saalim al-Faakihaani, the grammarian and Maaliki faqeeh (d. 734), who quoted it in his book al-Fajr al-Muneer, p. 31-32. He said:
The righteous shaykh Moosa ad-Dareer (may Allah have mercy on him) told me that he traveled by sea. He said: A wind called al-Aqlaabiyyah blew, from which hardly anyone could be saved from drowning, and the people panicked for fear of drowning. I was overtaken by sleep, and I saw (in my dream) the Prophet (blessings and peace of Allah be upon him), and he said: Tell the people of the ship to say one thousand times: “O Allah, send blessings upon our master Muhammad and upon the family of our master Muhammad, a blessing by virtue of which You will save us from all troubles and problems, by virtue of which You will meet all our needs, by virtue of which You will purify us of all sins, by virtue of which You will raise us with You at the highest levels, by virtue of which You will cause us to attain the highest levels of all good things, in this world and after death.”
He said: Then I woke up: and I told the people on the ship about the dream, and we recited this salawaat approximately 300 times, then we were granted relief. Blessings and peace of Allah be upon him. End quote.
It is well known that dreams and visions cannot be used as evidence for rulings or as the basis for righteous deeds, so it is not permissible to rely on them in order to prove the virtue of this format of sending blessings upon the Prophet (blessings and peace of Allah be upon him).
The religion of Allah, may He be exalted, is complete and perfect, as He says (interpretation of the meaning):
“This day, I have perfected your religion for you, completed My Favour upon you, and have chosen for you Islam as your religion”
The Messenger (blessings and peace of Allah be upon him) conveyed it to us in full and he did not conceal anything of it. Hence it is sufficient for the Muslim to follow that which is proven and soundly narrated from the Prophet (blessings and peace of Allah be upon him), and there is no need to prescribe any act of worship or regard it as mustahabb on the basis of dreams.
There are du‘aa’s that the Prophet (blessings and peace of Allah be upon him) used to say at times of distress or when overwhelmed by something.
Al-Bukhaari (6345) and Muslim (2730) narrated that Ibn ‘Abbaas (may Allah be pleased with him) said: The Prophet (blessings and peace of Allah be upon him) used to offer supplication at times of distress, saying: “La ilaaha ill-Allaah al-‘Azeem ul-Haleem, Laa ilaaha ill-Allaah Rabb is-samawaati wa Rabb il-ard wa Rabb il-‘arsh il-‘azeem (there is no god except Allaah, the All-Mighty, the Forbearing; there is no god except Allaah, Lord of the heavens, Lord of the earth and Lord of the mighty Throne).” According to the version narrated by Muslim: “wa Rabb il-‘arsh il-kareem (and Lord of the noble Throne).”
At-Tirmidhi (3524) narrated that Anas ibn Maalik (may Allah be pleased with him) said: the Prophet (peace and blessings of Allah be upon him) used to say, when something upset him:
“Yaa Hayyu yaa Qayyoom, bi Rahmatika astagheeth (O Ever-Living One, O Everlasting One, by Your mercy I seek help).”
Classed as hasan by al-Albaani in Saheeh at-Tirmidhi.
The Muslims should be keen to follow the Prophet (blessings and peace of Allah be upon him) and not introduce innovations into the religion. May Allah be pleased with ‘Abdullah ibn Mas‘ood who said: Follow and do not innovate, for whatever is (already) prescribed is sufficient for you. Narrated by ad-Daarimi, 205
We ask Allah, may He be exalted, to guide and help us to say and do that which is good.
And Allah knows best.