salam, can you please explain this hadith?
Sahih al-Tirmidhi and Sunan Abu Dawud, God’s Messenger declares: “The blessings of food lie in washing hands before and after eating.” (Abu Dawud,)
On the hadith itself
First there's no hadith in Jami' at-Tirmdihi nor Sunan abi Dawod saying:
God’s Messenger declares: “The blessings of food lie in washing hands before and after eating.” (Abu Dawud,)
as you may find here in the website of Fathullah Gülen which looks like an interpretation of the hadith.
The wording that has been compiled by the imam's at-Tirmidhi and abu Dawod is:
"I have read in-the Tauraah, that performing wudu (washing the hands) after eating increases blessings. I mentioned this to Rasulullah Sallailahu 'Alayhi Wasallam. Rasulullah Sallallahu 'Alayhi Wasallam said: "Wudu before and after eating (washing the hands and mouth) increases blessings."
(See in a-Shama'il al-Muhammadiya of imam at-Tirmdihi)
Abu Dawod -who compiled "before eating" instead of "after eating"- added:
Sufyan disapproved of performing ablution before taking food.
Abu Dawud said: It is weak. (See in Sunan abi Dawod)
And abu 'Eisa at-Tirmidhi added in his Jami':
He said: There are narrations on this topic from Anas and Abu Hurairah. [Abu 'Eisa said:] We do not know of this Hadith except as a narration of Qais bin Ar-Rabi'. Qais [bin Ar-Rabi'] was graded weak in Hadith. Abu Hashim Ar-Rumani's (a narrator in the chain) name is Yahya bin Dinar. (See in Jami' at-Tirmidhi)
On the sahabi who narrated it and the authenticity of the hadith
The hadith therefore is da'if due to the weak or even rejected narrator Qais ibn ar-Rabi'قَيْسُ بْنُ الرَّبِيعِ. The hadith was narrated on the authority of Salman al-Farisi سلمان الفارسي. As at-Tirmidhi said that Anas and abu Hurairah have narrated something on this topic:
On the authority of Anas ()
“The Messenger of Allah (ﷺ) said: ‘Whoever would like Allah to increase the goodness of his house, should perform ablution (wash hands) when his breakfast is brought to him and when it is taken away.’” (Sunan ibn Majah, qualified as da'if by al-Albani and others)
On the authority of abu Hurairah()
It was narrated from Abu Hurairah that the Messenger of Allah (ﷺ) went out to toilet, then food was brought. A man said: “O Messenger of Allah, are you not going to perform ablution?” He said: ‘Am I going to pray?’ (Sunan ibn Majah, qualified as sahih)
On the interpretation and ruling of this hadith
First the hadith states that Salman has studied the Torah before converting to Islam it also shows that he wanted to have a confirmation about a statement he read in there, but here already abu Dawod and at-Tirmidhi have differences one has said the Torah said that performing wudu' before eating increases blessings while the other say this is the case when performed after eating. The prophet () here might have indicated a corruption in the Torah or a better ruling in Islam when saying that performing it before and afterwards increases blessings.
Note that scholars interpret "wudu'" or washing hands here -as translated in the translation from imam at-Tirmidhi's a-Shamail al-Muhamadiya- refers to washing hands and washing the mouth (including rinsing the mouth).
They also say that the "wudu'" before eating is meant to clean the hands (for example) from the work done prior to eating and therefore the food would be more tasty and healthy after washing them, while the "wudu'" afterwards is to clean oneself from the traces of the food:
The Prophet (ﷺ) said: If anyone spends the night with grease on his hand which he has not washed away, he can blame only himself if some trouble comes to him. (See for example in Sunan abi Dawod and Jami' at-Tirmdihi, both are qualified as sahih)
and the blessings lays in things like being ready for worship after having eaten, and feeling better, easier etc..
Ibn Qayyim al-Jawziya said -according to Aabadi محمد شمس الحق العظيم آبادي in his 'Awn al-Ma'bud عون المعبود (the commentary on Sunan abi Dawod -see here in Arabic-) that scholars hold two different opinion on the matter of performing wudu' for eating food, one saying that it is recommended and the other that it is not recommended, both views are present in the madhhab of imam Ahmad and said the later is the most correct. He also statements and hadith narrations presented by imam a-Shafi'i supporting this. He also added a statement that Sufyan a-Thwari (the Sufyan abu Dawod was referring to) disliked performing wudu' prior to eating as it is something non-Arabs (maybe a reference to non-Muslims?) used to do. While Yahya ibn Ma'yn when asked about the hadith said there's nothing better than wudu' before and after eating. Imam Ahmad -who compiled it in his al-Musnad- also considered the hadith as da'if.
There are ahadiths upporting the opposite view such as:
"If the Messenger of Allah (ﷺ) wanted to sleep while he was Junub, he would perform Wudu', and if he wanted to eat or drink," she said: "he would wash his hands and then eat or drink." (Sunan an-Nasa'i, qualified as sahih, see also here and here)
As the prophet () said:
"I was sent to perfect good character." (Al-Muwatta')
we can consider washing hands and mouth before and after eating as a good maner which is allowed to perform and as both doing it or leaving it have been performed by the Prophet himself and narrated via the sahaba who witnessed it. Scholars are in consensus that when it comes to morals and good deeds we can rely on da'if ahadith.
Note that Islam is a concept of life so there's about no difference between the jurisprudence, theology and morals as morals are part of the Islamic jurisprudence.
See also in al-Mubarakpuri's محمد بن عبد الرحمن بن عبد الرحيم المباركفوري Tohfat al-Ahwadhi تحفة الأحوذي (Commentary on Jami' at-Tirmdihi) here in Arabic. And the fatwas on islamweb #222202 in Arabic and islqma #13348.