Sins and pardon have different degrees
Sins committed by not obeying the religious commandments, and the forgiveness thereof;
Sins committed by disobeying Allah (Subhaanahu Wa Ta’aalaa)’s laws of creation and life, and the forgiveness thereof;
Sins in respect of behaving against the rules of good manners or courtesy, and the forgiveness thereof.
A fourth type which is not a sin, is doing something good but not the best, a failure in doing perfectly what is required by the love of, and nearness to, Allah (Subhaanahu Wa Ta’aalaa). This is what some of the Prophets may have done, so it is not a sin in our normal usage of the word for something deserving of Divine punishment.
Tradition also proves the Prophets’ infallibility
Almighty Allah (Subhaanahu Wa Ta’aalaa) says in the Quraan concerning Prophet Hadhra Moosaa, what means:
وَأَلْقَيْتُ عَلَيْكَ مَحَبَّةً مِنِّي وَلِتُصْنَعَ عَلَى عَيْنِي [طه: 39]
“And I had cast love on you from Myself (so that you might be favorite of all), and that you might be brought up under My eye.” (TaaHaa 20:39)
Prophet Moosaa was brought up by Allah (Subhaanahu Wa Ta’aalaa) Himself and prepared for the mission of Messengership. Therefore, it is inconceivable that he may have committed a sin at any time in his life.
The same is true of all the other Prophets of Allah (Subhaanahu Wa Ta’aalaa). For example, Prophet Muhammad (SallAllaho Alaihe WaSallam) said of Prophet Eesaa (Jesus):
"Shaitaan (Satan) could not touch ‘Eesaa and his mother at his birth. Easaa was protected from birth until his elevation to the Presence of Allah, as we also read in the Quraan, what means:
فَأَشَارَتْ إِلَيْهِ قَالُوا كَيْفَ نُكَلِّمُ مَنْ كَانَ فِي الْمَهْدِ صَبِيًّا(٢٩) قَالَ إِنِّي عَبْدُ اللَّهِ آتَانِيَ الْكِتَابَ وَجَعَلَنِي نَبِيًّا(٣) وَجَعَلَنِي مُبَارَكًا أَيْنَ مَا كُنْتُ وَأَوْصَانِي بِالصَّلَاةِ وَالزَّكَاةِ مَا دُمْتُ حَيًّا(٣١) وَبَرًّا بِوَالِدَتِي وَلَمْ يَجْعَلْنِي جَبَّارًا شَقِيًّا(٣٢) وَالسَّلَامُ عَلَيَّ يَوْمَ وُلِدْتُ وَيَوْمَ أَمُوتُ وَيَوْمَ أُبْعَثُ حَيًّا٣٣ [مريم: 29-33]
“So, she (Maryum i.e. Mary) pointed towards him (the baby). They said, ‘How shall we speak to someone who is still a child in the cradle?’ Spoke he (the baby), ‘Verily I am the servant of Allah. He has given me the Book, and made me a prophet, and He has made me a blessed one wherever I be, and has enjoined Salaah (Prayers) and Zakaah (Obligatory Charity) upon me as long as I am alive, and (He has made me) good to my mother, and he did not make me oppressive (or) ill-fated. And peace is upon me the day I was born, the day I shall die, and the day I shall be raised alive again’.” (Maryum 19:29-33)
Hadhrat ‘Eesaa, like all the other Prophets, was protected from all kinds of sin from his birth. Prophet Muhammad (SallAllaho Alaihe WaSallam) intended in his childhood to attend two wedding ceremonies at different times but, on each occasion, he was overpowered by sleep which prevented him from attending. (Ibne Katheer, Al-Bidaayah, vol. 2, p.350-1)
Likewise, in his youth, he helped his uncles with the restoration of the Ka’bah (Sacred House in Makkah al Mukarramah) by carrying stones. Since the stones hurt his shoulders, his uncle, Al-‘Abbas advised him to hoist the garment covering the lower part of his body, onto his shoulder to carry the stones on. He just did what he was advised to do, leaving very little portion of the upper part of his legs uncovered, as having long shirt on him, when he fell on his back with his eyes staring fixedly. An angel appeared and warned him that what he had done was improper, saying: ‘This is not befitting for you.’ (Bukhari)
For the day was to come when he would order people to be well-mannered and observe divinely ordained standards of conduct, including covering the thighs.
Allah (Subhaanahu Wa Ta’aalaa)’s Messenger (SallAllaho Alaihe WaSallam) says that all the children of Adam make faults and err, and the best of those who make faults and err are the repentant. (At-Tirmizi)
This implies that man is fallible by nature, but it does not mean that all of mankind are ‘condemned’ to erring whosoever. Whether by Allah (Subhaanahu Wa Ta’aalaa)’s Will and special protection or, as will be explained below, by His showing the way to be free from errors or sins.
Allah (Subhaanahu Wa Ta’aalaa) promises to protect the believers who fear Him, and to endow them with sound judgment to enable them to distinguish between truth and falsehood, and between right and wrong. Allah (Subhaanahu Wa Ta’aalaa), the Most Exalted, says, what means:
وَاعْلَمُوا أَنَّمَا أَمْوَالُكُمْ وَأَوْلَادُكُمْ فِتْنَةٌ وَأَنَّ اللَّهَ عِنْدَهُ أَجْرٌ عَظِيمٌ [الأنفال: 28]
“Be aware that your wealth and your children are but a trial and that with Allah there is a great reward.” (Al-Anfaal 8:28)
Allah (Subhaanahu Wa Ta’aalaa) made a covenant with the believers that if they obey Him, assist His cause, He will help them and make their feet firm in the religion, protecting them against all kinds of deviation.
يَا أَيُّهَا الَّذِينَ آمَنُوا إِنْ تَنْصُرُوا اللَّهَ يَنْصُرْكُمْ وَيُثَبِّتْ أَقْدَامَكُمْ [محمد: 7]
“O you who believe! If you will help (the religion prescribed by) Allah, He will help you, and will stabilize your footings.” (Muhammad 47:7)
Allah (Subhaanahu Wa Ta’aalaa)’s protection of believers from their enemies and against committing sins has been made dependent on their support of Islam and struggle to spread it all over the world so that only Allah (Subhaanahu Wa Ta’aalaa) is worshipped and no partners are associated with Him either in belief or worship or the creation and rule of the universe. If believers fulfill their covenant with Allah (Subhaanahu Wa Ta’aalaa), He will fulfill His covenant with them.
يَا بَنِي إِسْرَائِيلَ اذْكُرُوا نِعْمَتِيَ الَّتِي أَنْعَمْتُ عَلَيْكُمْ وَأَوْفُوا بِعَهْدِي أُوفِ بِعَهْدِكُمْ وَإِيَّايَ فَارْهَبُونِ [البقرة: 40]
“…….. remember My blessing that I conferred upon you, and fulfill the covenant with Me, and I shall fulfill your covenant, and have awe of Me alone.” (Al-Baqarah 2:40)
If, by contrast, they break their promise, Allah (Subhaanahu Wa Ta’aalaa) will not make them successful.
عَسَى رَبُّكُمْ أَنْ يَرْحَمَكُمْ وَإِنْ عُدْتُمْ عُدْنَا وَجَعَلْنَا جَهَنَّمَ لِلْكَافِرِينَ حَصِيرًا [الإسراء: 8]
“But if you do this again, We shall do that again, and We have made Jahannam (Hell) a prison for the disbelievers.” (Al-Israa 17:8)
Allah (Subhaanahu Wa Ta’aalaa) protects His servants against sins in different ways. He may put some obstacles in their way to sins so they do not commit sin, or He may establish a ‘Warner’ in their hearts, or, if all the other means prove of no use, He may cause, for example, their legs to be broken or their hands unable to hold or grasp. Or He may warn one by putting an Aayat in his mouth, as He did with a young man during the Caliphate of ‘Umar.
The young man was so strict and attentive in his worship that he performed all his Salaah (Prayers) in the Masjid. A woman lived on his way to the Masjid and tried her hardest for several days to seduce him into making love with her. Although the young man resisted her alluring gestures, the moment came when he took a few steps towards the woman’s house. Just at this point, he felt he was reciting this Aayah, which means:
إِنَّ الَّذِينَ اتَّقَوْا إِذَا مَسَّهُمْ طَائِفٌ مِنَ الشَّيْطَانِ تَذَكَّرُوا فَإِذَا هُمْ مُبْصِرُونَ [الأعراف: 201]
“Surely when the Allah-fearing are touched by any instigation from Satan, they become conscious (of Allah), and at once they discern (the reality).” (Al-A’raaf 7:201)
In the face of this Divine warning, the young man was so ashamed before Allah (Subhaanahu Wa Ta’aalaa) of what he was about to do, and felt so overwhelmed by his Compassionate Lord’s preventing him from committing a sin, that he died. When Hadhrat ‘Umar was informed of the incident a few days later, he went to his grave and said in aloud: ‘O young man!
وَلِمَنْ خَافَ مَقَامَ رَبِّهِ جَنَّتَانِ [الرحمن: 46]
“And for the one who is fearful of having to stand before his Lord, there are two gardens,” (Ar-Rahmaan 55:46)
A voice from the grave, whether belonging to the young man himself or an angel on his behalf, replied: ‘O Commander of the Believers: Allah has granted me the double of what you say!’ (Tafseer Ibne Katheer, vol. 3, p. 539)
This is Allah (Subhaanahu Wa Ta’aalaa)’s protection of His sincere servants. He says in one of His Revelations outside the Quraan (Hadeeth Qudsi):
"My servant cannot draw near to me through something else more lovable to Me than the obligations I have enjoined upon him. Apart from those obligations, he continues to draw near to Me through supererogatory acts of worship, until I love him. When I love him, I will be his ears with which he hears, his eyes with which he sees, his hands with which he grasps, and his feet on which he walks. If he asks Me something, I will immediately give it to him; if he seeks refuge in Me from something, I will protect him from it.” (Bukhari)
Allah (Subhaanahu Wa Ta’aalaa) guides His true servant to good and protects him from all kinds of evil. The servant wills and does what is good and refrains from wickedness. He asks Allah (Subhaanahu Wa Ta’aalaa) what is good and whatever he asks is provided for him; he seeks refuge in Allah (Subhaanahu Wa Ta’aalaa) from what is bad, and whatever he seeks refuge in Allah (Subhaanahu Wa Ta’aalaa) from, he is protected against it.
All the Prophets of Allah (Subhaanahu Wa Ta’aalaa) were infallible. They never committed a sin, minor or major, and their lives were spent doing virtuous deeds.