Allah the Exalted said,

﴿ظ‡ظڈظˆظژ ط§ظ„ظ‘ظژط°ظگظ‰ ط£ظژظ†ط²ظژظ„ظژ ط§ظ„ط³ظ‘ظژظƒظگظٹظ†ظژط©ظژ﴾

(He it is Who sent down As-Sakinah), meaning, tranquility. Qatadah commented, "Grace into the hearts of the believers'', that is, the Companions, may Allah be pleased with them, on the Day of Al-Hudaybiyyah. The companions were they, who accepted the call of Allah and His Messenger and obeyed the decisions of Allah and His Messenger . When their hearts felt content with acceptance and were at peace, Allah increased their faith, joining it to the faith they already had. Al-Bukhari, and other Imams, relied on this Ayah as proof that faith increases and decreases in the hearts. Allah the Exalted said next that had He willed, He would have inflicted defeat on the disbelievers, Allah says;

﴿ظˆظژظ„ظگظ„ظ‘ظژظ‡ظگ ط¬ظڈظ†ظڈظˆط¯ظڈ ط§ظ„ط³ظ‘ظژظ…ظژظ€ظˆظژطھظگ ظˆظژط§ظ„ط§ظ‘ظŒط±ظ’ط¶ظگ﴾

(And to Allah belong the armies of the heavens and the earth) and had He willed to send only one angel to them, that angel would have brought destruction to all what they had. However, Allah the Exalted willed Jihad and fighting to be established for, and by, the believers for great wisdom, clear reasons and unequivocal evidences that He had in all this. This is why Allah the Great said next,

﴿ظˆظژظƒظژط§ظ†ظژ ط§ظ„ظ„ظ‘ظژظ‡ظڈ ط¹ظژظ„ظگظٹظ…ط§ظ‹ ط­ظژظƒظگظٹظ…ط§ظ‹﴾

(and Allah is Ever All-Knower, All-Wise.) Allah the Exalted and Most Honored said,

﴿ظ„ظ‘ظگظٹظڈط¯ظ’ط®ظگظ„ظژ ط§ظ„ظ’ظ…ظڈط¤ظ’ظ…ظگظ†ظگظٹظ†ظژ ظˆظژط§ظ„ظ’ظ…ظڈط¤ظ’ظ…ظگظ†ظژظ€طھظگ ط¬ظژظ†ظ‘ظژظ€طھظچ طھظژط¬ظ’ط±ظگظ‰ ظ…ظگظ† طھظژط­ظ’طھظگظ‡ظژط§ ط§ظ„ط§ظ‘ظŒظ†ظ’ظ‡ظژظ€ط±ظڈ ط®ظژظ€ظ„ظگط¯ظگظٹظ†ظژ ظپظگظٹظ‡ظژط§﴾

(That He may admit the believing men and the believing women to Gardens under which rivers flow to abide therein forever,) We mentioned the Hadith that Anas narrated in which the Companions said, "Congratulations, O Allah's Messenger! This good news is for you, so what good news do we have'' Allah the Exalted sent down this Ayah,

﴿ظ„ظ‘ظگظٹظڈط¯ظ’ط®ظگظ„ظژ ط§ظ„ظ’ظ…ظڈط¤ظ’ظ…ظگظ†ظگظٹظ†ظژ ظˆظژط§ظ„ظ’ظ…ظڈط¤ظ’ظ…ظگظ†ظژظ€طھظگ ط¬ظژظ†ظ‘ظژظ€طھظچ طھظژط¬ظ’ط±ظگظ‰ ظ…ظگظ† طھظژط­ظ’طھظگظ‡ظژط§ ط§ظ„ط§ظ‘ظŒظ†ظ’ظ‡ظژظ€ط±ظڈ ط®ظژظ€ظ„ظگط¯ظگظٹظ†ظژ ظپظگظٹظ‡ظژط§﴾

(That He may admit the believing men and the believing women to Gardens under which rivers flow to abide therein forever,) meaning they will remain in Paradise forever,

﴿ظˆظژظٹظڈظƒظژظپظ‘ظگط±ظژ ط¹ظژظ†ظ’ظ‡ظڈظ…ظ’ ط³ظژظٹظ‘ظگط¦ظژظ€طھظگظ‡ظگظ…ظ’﴾

(and He may expiate from them their sins;) Allah will not punish them for their errors and mistakes. Rather, He will forgive, absolve and pardon them and cover the errors, grant mercy and appreciate,

﴿ظˆظژظƒظژط§ظ†ظژ ط°ظژظ„ظگظƒظژ ط¹ظگظ†ط¯ظژ ط§ظ„ظ„ظ‘ظژظ‡ظگ ظپظژظˆظ’ط²ط§ظ‹ ط¹ظژط¸ظگظٹظ…ط§ظ‹﴾

(and that is with Allah supreme success.) Allah the Exalted said in a similar Ayah,

﴿ظپظژظ…ظژظ† ط²ظڈط­ظ’ط²ظگط­ظژ ط¹ظژظ†ظگ ط§ظ„ظ†ظ‘ظژط§ط±ظگ ظˆظژط£ظڈط¯ظ’ط®ظگظ„ظژ ط§ظ„ظ’ط¬ظژظ†ظ‘ظژط©ظژ ظپظژظ‚ظژط¯ظ’ ظپظژط§ط²ظژ﴾

(And whoever is removed away from the Fire and admitted to Paradise, he indeed is successful.) (3:185) Allah said,

﴿ظˆظژظٹظڈط¹ظژط°ظ‘ظگط¨ظژ ط§ظ„ظ’ظ…ظڈظ†ظژظ€ظپظگظ‚ظگظٹظ†ظژ ظˆظژط§ظ„ظ’ظ…ظڈظ†ظژظ€ظپظگظ‚ظژظ€طھظگ ظˆظژط§ظ„ظ’ظ…ظڈط´ظ’ط±ظگظƒظگظٹظ†ظژ ظˆظژط§ظ„ظ’ظ…ظڈط´ظ’ط±ظگظƒظژظ€طھظگ ط§ظ„ط¸ظ‘ظژط¢ظ†ظ‘ظگظٹظ†ظژ ط¨ظگط§ظ„ظ„ظ‘ظژظ‡ظگ ط¸ظژظ†ظ‘ظژ ط§ظ„ط³ظ‘ظژظˆظ’ط،ظگ﴾

(And that He may punish the hypocrites, men and women, and also the idolators, men and women, who think evil thoughts about Allah,) who question the wisdom in Allah's decisions and think that the Messenger and his Companions, may Allah be pleased with them, might be killed and exterminated. This is why Allah the Exalted said,

﴿ط¹ظژظ„ظژظٹظ’ظ‡ظگظ…ظ’ ط¯ظژط¢ط¦ظگط±ظژط©ظڈ ط§ظ„ط³ظ‘ظژظˆظ’ط،ظگ ظˆظژط؛ظژط¶ظگط¨ظژ ط§ظ„ظ„ظ‘ظژظ‡ظڈ ط¹ظژظ„ظژظٹظ’ظ‡ظگظ…ظ’ ظˆظژظ„ظژط¹ظژظ†ظژظ‡ظڈظ…ظ’﴾

(for them is a disgraceful torment. And the anger of Allah is upon them, and He has cursed them) He has cast them away from His mercy,

﴿ظˆظژط£ظژط¹ظژط¯ظ‘ظژ ظ„ظژظ‡ظڈظ…ظ’ ط¬ظژظ‡ظژظ†ظ‘ظژظ…ظژ ظˆظژط³ظژط¢ط،ظژطھظ’ ظ…ظژطµظگظٹط±ط§ظ‹﴾

(and prepared Hell for them -- and worst indeed is that destination.) Allah the Exalted and Most Honored asserted His ability to take revenge from the enemies of Islam and all disbelievers and hypocrites,

﴿ظˆظژظ„ظگظ„ظ‘ظژظ‡ظگ ط¬ظڈظ†ظڈظˆط¯ظڈ ط§ظ„ط³ظ‘ظژظ…ظژظ€ظˆظژطھظگ ظˆظژط§ظ„ط§ظ‘ظŒط±ظ’ط¶ظگ ظˆظژظƒظژط§ظ†ظژ ط§ظ„ظ„ظ‘ظژظ‡ظڈ ط¹ظژط²ظگظٹط²ط§ظ‹ ط­ظژظƒظگظٹظ…ط§ظ‹ ﴾

(And to Allah belong the armies of the heavens and the earth. And Allah is Ever All-Powerful, All-Wise.)

﴿ط¥ظگظ†ظ‘ظژط¢ ط£ظژط±ظ’ط³ظژظ„ظ’ظ†ظژظ€ظƒظژ ط´ظژظ€ظ‡ظگط¯ط§ظ‹ ظˆظژظ…ظڈط¨ظژط´ظ‘ظگط±ط§ظ‹ ظˆظژظ†ظژط°ظگظٹط±ط§ظ‹ - ظ„ظ‘ظگطھظڈط¤ظ’ظ…ظگظ†ظڈظˆط§ظ’ ط¨ظگط§ظ„ظ„ظ‘ظژظ‡ظگ ظˆظژط±ظژط³ظڈظˆظ„ظگظ‡ظگ ظˆظژطھظڈط¹ظژط²ظ‘ظگط±ظڈظˆظ‡ظڈ ظˆظژطھظڈظˆظژظ‚ظ‘ظگط±ظڈظˆظ‡ظڈ ظˆظژطھظڈط³ظژط¨ظ‘ظگط­ظڈظˆظ‡ظڈ ط¨ظڈظƒظ’ط±ظژط©ظ‹ ظˆظژط£ظژطµظگظٹظ„ط§ظ‹ - ط¥ظگظ†ظ‘ظژ ط§ظ„ظ‘ظژط°ظگظٹظ†ظژ ظٹظڈط¨ظژط§ظٹظگط¹ظڈظˆظ†ظژظƒظژ ط¥ظگظ†ظ‘ظژظ…ظژط§ ظٹظڈط¨ظژط§ظٹظگط¹ظڈظˆظ†ظژ ط§ظ„ظ„ظ‘ظژظ‡ظژ ظٹظژط¯ظڈ ط§ظ„ظ„ظ‘ظژظ‡ظگ ظپظژظˆظ’ظ‚ظژ ط£ظژظٹظ’ط¯ظگظٹظ‡ظگظ…ظ’ ظپظژظ…ظژظ† ظ†ظ‘ظژظƒظژط«ظژ ظپظژط¥ظگظ†ظ‘ظژظ…ظژط§ ظٹظژظ†ظƒظڈط«ظڈ ط¹ظژظ„ظژظ‰ ظ†ظژظپظ’ط³ظگظ‡ظگ ظˆظژظ…ظژظ†ظ’ ط£ظژظˆظ’ظپظژظ‰ ط¨ظگظ…ظژط§ ط¹ظژظ€ظ‡ظژط¯ظژ ط¹ظژظ„ظژظٹظ’ظ‡ظگ ط§ظ„ظ„ظ‘ظژظ‡ظژ ظپظژط³ظژظٹظڈط¤ظ’طھظگظٹظ‡ظگ ط£ظژط¬ظ’ط±ط§ظ‹ ط¹ظژط¸ظگظٹظ…ط§ظ‹ ﴾

(8. Verily, We have sent you as a witness, as a bearer of glad tidings, and as a warner.) (9. In order that you (O mankind) may believe in Allah and His Messenger and that you Tu`azziruh and Tuwaqqiruh, and Tusabbihuh Bukrah and Asila.) (10. Verily, those who give pledge to you, they are giving pledge to Allah. The Hand of Allah is over their hands. Then whosoever breaks his pledge, breaks it only to his own harm; and whosoever fulfills what he has the covenants he makes with Allah, He will bestow on him a great reward.)