As for the principle, it is that the deeds of man are not sufficient to deliver him from Hellfire, or to grant him entry into Paradise; instead this can only come about through the mercy of Allah and His forgiveness. The Quran supports this meaning in many places such as His sayings,
Those who migrated and were driven from their homes and suffered harm in My way and fought and were killed, I will erase their bad actions from them and admit them into Gardens with rivers flowing beneath them as a reward from Allah [Al-Imran, 195]
Their Lord gives them the good news of his mercy and good pleasure and Gardens where they will enjoy everlasting delight, remaining in them timelessly, forever and ever [Tawbah, 22]
...it is to believe in Allah and His Messenger and to do Jihad in the Way of Allah with your wealth and yourselves. That is better for you if you only knew. He will forgive you your wrong actions and admit you into Gardens with rivers flowing beneath them... [as-Saff, 11-12]
mentioning victory and entry into Paradise alongside forgiveness and mercy thereby proving that this cannot be attained except by these.
Some of the Salaf said, 'The Hereafter consists either of Allah's forgiveness or the Fire; and this world is either a source of Allah's protection or a source of destruction.' On his death bed; Muhammad ibn Wasi bid farewell to his companions saying, 'Peace be upon you, either to the Fire or to the forgiveness of Allah.' [Al-Hilyah]
As for the saying of Allah,
That is the Garden you will be made to inherit for what you did. [al-Zukhruf, 72]
...eat and drink with relish for what you did before in days gone by! [al-Haqqah, 24]
the scholars differed concerning the meaning of this, falling into two opinions:
Therefore actual entry into Paradise is dependant upon the grace of Allah, His forgiveness and mercy: He is the one who blessed the person with the means and the result of that means. Hence entry is not a direct outcome of actions in and of themselves. It is recorded in the Sahih that the Prophet (saw) said, "Allah, Blessed and Exalted, said to Paradise: You are My mercy, I show mercy through you to whoever I will of My servants."
The servants have no right over Him that He must render, Never! Neither, in His presence, is any effort wretched. If they are punished, then by His Justice; if they are in bliss, Then by His beneficence. He is the Kind, the Vast.
The Great Principle
Al-hamdulillah is the Imbursement of every Favour
Elucidation of the Meaning of Favours
Both Paradise & Deeds are from the Grace of Allah
Misery and Felicity Occur through His Justice and Mercy
Allah's Blessings can Never be Truly Repaid
One of the Greatest Blessings is Gratitude
Acknowledging the Grace of Allah
The Most Beloved Deeds to Allah
The Meaning of "Saddidu wa Qaribu"
A Noble Principle
The Ease of this Religion
The Meaning of "the beginning of the day", "the end of the day," & "a portion of the latter part of the night"
The Meaning of Moderation
Travelling the Path of Allah, Mighty and Magnificent
Deeds are by their Conclusion
The Excellence of Drawing Close to Allah
The Types of Reaching Allah
Islam, Iman, Ihsan
The Periods of Morning and Evening
Those who Hold to the World and those who Hold on to the Hereafter
The Unexpected Confrontation
The Types of Actions that will be as Scattered Dust
Sadness in the World & Misery in the Hereafter