Allah said:

﴿فَمَن لَّمْ يَجِدْ فَصِيَامُ ثَلَـثَةِ أَيَّامٍ فِي الْحَجِّ وَسَبْعَةٍ إِذَا رَجَعْتُمْ تِلْكَ عَشَرَةٌ كَامِلَةٌ﴾

(...but if he cannot (afford it), he should fast three days during the Hajj and seven days after his return (to his home), making ten days in all.)

This Ayah means: "Those who do not find a Hady, let them fast three days during the Hajj season.'' Al-`Awfi said that Ibn `Abbas said, "If one does not have a Hady, he should fast three days during Hajj, before `Arafah day. If the day of `Arafah was the third day, then his fast is complete. He should also fast seven days when he gets back home.'' Abu Ishaq reported from Wabarah from Ibn `Umar who said, "One fasts one day before the day of Tarwiyah, the day of Tarwiyah (eighth day of Dhul-Hijjah) and then `Arafah day (the ninth day of the month of Dhul-Hijjah).'' The same statement was reported by Ja`far bin Muhammad from his father from `Ali.

If one did not fast these three days or at least some of them before `Id day (the tenth day of Dhul-Hijjah), he is allowed to fast during the Tashriq days (11-12-13th day of Dhul-Hijjah). `A'ishah and Ibn `Umar said, "Fasting the days of Tashriq was only allowed for those who did not find the Hady,'' as Al-Bukhari has reported. Sufyan related that Ja`far bin Muhammad narrated that his father said that `Ali said, "Whoever did not fast the three days during the Hajj, should fast them during the days of Tashriq.'' This is also the position taken by `Ubayd bin `Umayr Al-Laythi, `Ikrimah, Al-Hasan Al-Basri and `Urwah bin Az-Zubayr, referring to the general meaning of Allah's statement:

﴿فَصِيَامُ ثَلَـثَةِ أَيَّامٍ فِي الْحَجِّ﴾

(...fast three days during the Hajj...)

As for what Muslim reported that Qutaybah Al-Hudhali said that Allah's Messenger said:

«أَيَّامُ التَّشْرِيقِ أَيَّامُ أَكْلٍ وَشُرْبٍ، وَذِكْرِ اللهِ عَزَّ وَجَل»

(The days of Tashriq are days of eating and drinking and remembering Allah the Exalted.)

This narration is general in meaning while what `A'ishah and Ibn `Umar narrated is specific.

Allah said:

﴿وَسَبْعَةٍ إِذَا رَجَعْتُمْ﴾

(...and seven days after his return.)

There are two opinions regarding the meaning of this Ayah. First, it means `when you return to the camping areas'. The second, upon going back home. `Abdur-Razzaq reported that Salim narrated that he heard Ibn `Umar saying:

﴿فَمَن لَّمْ يَجِدْ فَصِيَامُ ثَلَـثَةِ أَيَّامٍ فِي الْحَجِّ وَسَبْعَةٍ إِذَا رَجَعْتُمْ﴾

"(...but if he cannot (afford it), he should fast three days during the Hajj and seven days after his return,) means when he goes back to his family. '' The same opinion was reported from Sa`id bin Jubayr, Abu Al-`Aliyah, Mujahid, `Ata', `Ikrimah, Al-Hasan, Qatadah, Imam Az-Zuhri and Ar-Rabi` bin Anas.

Al-Bukhari reported that Salim bin `Abdullah narrated that Ibn `Umar said, "During the Farewell Hajj of Allah's Messenger , he performed Tamattu` with `Umrah and Hajj. He drove a Hady along with him from Dhul-Hulayfah. Allah's Messenger started by assuming Ihram for `Umrah, and then for Hajj. And the people, too, performed the `Umrah and Hajj along with the Prophet . Some of them brought the Hady and drove it along with them, while the others did not. So, when the Prophet arrived at Makkah, he said to the people:

«مَنْ كَانَ مِنْكُم أَهْدَى فَإِنَّهُ لَا يَحِلُّ مِنْ شَيْءٍ حَرُمَ مِنْهُ حَتَّى يَقْضِيَ حَجَّهُ، وَمَنْ لَمْ يَكُنْ مِنْكُمْ أَهْدَى فَلْيَطُفْ بالْبَيْتِ وبالصَّفَا وَالْمَرْوَةِ وَلْيُقَصِّرْ وَلْيَحْلِلْ، ثُمَّ لْيُهِلَّ بِالْحَجِّ، فَمَنْ لَمْ يجَدْ هَدْيًا فَلْيَصُمْ ثَلَاثَةَ أَيَّامٍ فِي الْحَجِّ، وَسَبْعةً إِذَا رَجَعَ إِلى أَهْلِه»

(Whoever among you has driven the Hady, should not finish his Ihram till he completes his Hajj. And whoever among you has not (driven) the Hady with him, he should perform Tawaf of the Ka`bah and between As-Safa and Al-Marwah. Then, he should shave or cut his hair short and finish his Ihram, and should later assume Ihram for Hajj; ﴿but he must offer a Hady (sacrifice)﴾. And if anyone cannot afford a Hady, he should fast for three days during the Hajj and seven days when he returns home.)

He then mentioned the rest of the Hadith, which is reported in the Two Sahihs.

Allah said:

﴿تِلْكَ عَشَرَةٌ كَامِلَةٌ﴾

(...making ten days in all.) to emphasize the ruling we mentioned above. This method is common in the Arabic language, for they would say, `I have seen with my eyes, heard with my ears and written with my hand,' to emphasize such facts. Similarly, Allah said:

﴿وَلاَ طَائِرٍ يَطِيرُ بِجَنَاحَيْهِ﴾

(...nor a bird that flies with its two wings) (6:38) and:

﴿وَلاَ تَخُطُّهُ بِيَمِينِكَ﴾

(...nor did you write any book (whatsoever) with your right hand) (29:48) and:

﴿وَوَعَدْنَا مُوسَى ثَلَـثِينَ لَيْلَةً وَأَتْمَمْنَاهَا بِعَشْرٍ فَتَمَّ مِيقَـتُ رَبِّهِ أَرْبَعِينَ لَيْلَةً﴾

(And We appointed for Musa thirty nights and added (to the period) ten (more), and he completed the term, appointed by his Lord, of forty nights.) (7:142)

It was also said that the meaning of "ten days in all'' emphasizes the order to fast for ten days, not less than that.