Virtues of Salawat: Introduction to 'Al-Khair al-Kathir'
All praise is due to Allah for the abundant good, blessings and peace upon the giver of glad tidings and the warner, our master Muhammad the unlettered, and upon his family, companions, wives, household and group.
I bear witness that there is no god except Allah alone who has no partner, a testimony which benefits the one who says it on the day of resurrection and questioning. I bear witness that our master Muhammad is His (Allah’s) slave and messenger, Allah is his master who perfected him, His beloved whom He esteemed and beautified, and His Prophet whom He sent to the whole of creation, and was given excellence over all of the Prophets and Messengers, and ennobled and honoured, and specified him with greatness and exalted. Upon him and family and companions the most excellent blessings and peace.
To proceed: These are forty hadith on sending blessings and peace upon the noble Prophet (Allah bless him and give him peace), and that which is reported regarding their blessings and excellence/virtue, and the felicity of those who do this. And that which is reported regarding the immense reward for those who practise it, and the one who is consistent with it in his night and day.
A large number of the scholars (Allah be pleased with them) have authored countless number (of works) in this area whose scope is not hidden.
Al-Nawawi –Allah have mercy on him- mentioned in his ‘Arbaeen’ a number of them, may Allah be pleased with them. They compiled these acting upon his (Allah bless him and give him peace) words: ‘Whosoever memorises and preserves for my people forty hadith relating to their religion, Allah (the most High) will resurrect him on the Day of Judgment in the company of jurists and religious scholars’ .
The scholars of hadith –Allah be pleased with them- said: The meaning of memorizing here is: to transmit it to the Muslims, even if they do not memorize them, nor know their meanings. This is the reality of what it means, and by this benefit is attained/obtained for the Muslims Inshallah.
I saw that I should compile them on sending blessings and peace upon the best of mankind, because it is the greatest gift a slave can present before Him. And most noble treasure the one who reaps can save for the day he is questioned by Him. I compiled it from the well known books on this subject, desiring to attain recompense and reward. I have compiled it without the chains of transmission so that it is easy for its readers, and organised it in a fine manner indicating to the various forms of its excellence/virtue. I have explained its difficult wording to make clear the matter for those who memorize it. I have divided it into chapters and it is the same number as the doors of paradise, and for Allah is the praise and kindness.
The first Chapter is: The large reward of the one who sends blessings upon our master the Messenger of Allah (Allah bless him and give him peace)
Second Chapter: The excellence/virtue of blessings upon our master the Messenger of Allah (Allah bless him and give him peace)
Third Chapter: On sending many blessings upon our master the Messenger of Allah (Allah bless him and give him peace)
Fourth Chapter: On asking for wasilah for him along with blessings on him (Allah bless him and give him peace)
Fifth Chapter: On the blessings reaching our master the Messenger of Allah (Allah bless him and give him peace)
Sixth Chapter: On the necessity of blessings upon our master the Messenger of Allah (Allah bless him and give him peace)
Eighth Chapter: On sending peace upon our master the Messenger of Allah (Allah bless him and give him peace)
This is the sum of the chapters contained within it, and is easily accessible to students/seekers. I have cited in each chapter five from the forty, and upon Allah I rely and I seek help from. I have named it:
The abundant reward in blessings and peace upon the giver of glad tidings and warner
 Meaning collections of forty hadith
 This is in the introduction of his ‘Arbaeen’ where he mentioned Abdullah bin al-Mubarak, Muhammad bin Aslam al-Tusi and nine others. A large number of others can be found in ‘Al-Risalah al-Mustatrifah’ of al-Sayyid Muhammad Ibn Jafar al-Kattani (p.102-104).
 Refer to its various wordings and referencing in the treatise of al-Hafidh Ahmad bin al-Siddiq al-Ghumari (Allah have mercy on him) in his ‘Irshad al-Marbaeen ila Tareeq Hadith al-Arbaeen’ which was published in Egypt in the year 1354 (hijri).
The hadith is well known as being weak along with its numerous chains of transmission, except that Imam Ibn Asakir discussion in his work ‘Al-Arbaeen al-Buldaniyyah’ (p.44) indicates to his leaning towards the strengthening of hadith due to its numerous chains of transmission, and al-Hafidh al-Ghumari ended his treatise with a mention of this, as if he also leans towards this view. And Allah knows best.