Fasting on Ashura.
Because the Prophet, may God bless him and grant him peace:
(He was asked about fasting on the day of Ashura, then he said: I count upon God to expiate the Sunnah that preceded it.) (Collected by Muslim (1162) on the authority of Abu Qatada, may God be pleased with him.)
Then followed by the ninth:
For his saying, peace be upon him, (If I lived to a midwife, I would fast for the ninth) (Reported by Muslim 2/819 on the authority of Abu Abbas, may God be pleased with him.)
Means with x.
Q / Do individuals hate the tenth?
It was said: It is makrooh for the hadeeth (fast on the day of Ashura, and disagree with the Jews in it, fast a day before or after it) (Al-Judeo’s narrated by Ahmad Abbas and Al-Musnad 4 / 9th day).
And it was said: It is not makrooh. (The Sheikh of Islam said in al-Ikhtitiarah (110) (and fasting the day of Ashura is a year’s expiation, and it is not disliked to single out fasting)
But he does not get the full wage if he singles out.

Q / The tenth fast is more difficult than the ninth, or hardened during the rest of the days. What is the reason for that?
Because this is the day on which God delivered Moses and his people, and destroyed Pharaoh and his people.
Modern :
(.Kdm Prophet peace be upon him the city and saw the Jews fasting the day of Ashura, he said: What is this? They said: This is a good day, this day Allaah saved the children of Israel from their enemy, Vsamh Moussa, he said I am more deserving of Moses you, fasted and ordered to fast.) ( Collected by Al-Bukhari (2004) and Muslim (1130) (128)) (Al-Sharh Al-Mumti 'on Zad Al-Mughrabi by Sheikh Muhammad Al-Uthaymeen 6/471)
Most of the scholars went: fasting it was obligatory, then it was abrogated by fasting Ramadan.

Q / What is the advantage of fasting the day of Ashura?
His merit: An expiation for the past year, as Sheikh Al-Islam Ibn Taymiyyah stated:
(Fasting the Day of Ashura is an expiation for a Sunnah ....) (In al-Ikhtiyara, p. 110 by Sheikh al-Islam Ibn Taymiyyah)
Hadith: “I count upon God to make atonement for the Sunnah before it

”

* The love of the Messenger, may God bless him and grant him peace, comes from faith. 14 - Abu Al-Yaman told us, he said: Sha`aib told us, he said: Abu Al-Zinad told us, on the authority of Al-Araj, on the authority of Abu Hurayrah Radhi The Messenger of God, may God’s prayers and peace be upon him, said: “And the one who has a soul in his hand does not believe one of you until I love him more than his father and his son.” (So ​​I swear by God Almighty, whose life is in His hand.) (I love him) in advance and has the address of that obedience and following the example and leaving the violation.

 15 - Yaqoub Ibn Ibrahim told us, he said: Ibn Aliya spoke to us from Abd al-Aziz ibn Sahib On the authority of Anas who said: The Prophet, may God’s prayers and peace be upon him, said: “None of you believes, until I love him more than his father, his son and all the people.” W15 (1/14) - [U included by Muslim in the chapter on the necessity of loving the Messenger of God, may God bless him and grant him peace, more than the family, the child and the father No.44]

Muhammad ibn al-Muthanna told us, he said: Abd al-Wahhab al-Thaqafi spoke to us, he said: Job told us about Abu Qalabah on the authority of Ali
On the authority of the Prophet, may God’s prayers and peace be upon him, said:
"Be three of which found the sweetness of faith: that God and His Messenger are dearer to him than all else, and that one does not love God only loves, and hates to go back in disbelief as he would hate to be thrown into the fire" W16 (1/14) - [U narrate...d by Muslim in Faith, chapter on describing the qualities of those who characterize them and found the sweetness of faith No. 43
(He found the sweetness of faith) His chest was open to faith, and he enjoyed obedience and endured hardships in religion.
And sweetness in the language is a sweet source which is the opposite of bitterness.
(He does not love him except for God) does not mean his love for a worldly purpose.
(Tossing) throws. (12, 5694, 6542)