It is permissible to enter Makkah without Ihram

Anas b. Malik (Allah be pleased with them) reported that Allah's Apostle ﷺ entered Mecca in the Year of Victory with a helmet on his head;
and when he took it off, a man came to him and said: Ibn Khatal is hanging on to the curtains of the Ka'ba, whereupon he said: Kill him. Malik (one of the narrators) attested this statement having been made.

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ الْقَعْنَبِيُّ، وَيَحْيَى بْنُ يَحْيَى، وَقُتَيْبَةُ بْنُ سَعِيدٍ، أَمَّا الْقَعْنَبِيُّ فَقَالَ قَرَأْتُ عَلَى مَالِكِ بْنِ أَنَسٍ وَأَمَّا قُتَيْبَةُ فَقَالَ حَدَّثَنَا مَالِكٌ وَقَالَ يَحْيَى - وَاللَّفْظُ لَهُ - قُلْتُ لِمَالِكٍ أَحَدَّثَكَ ابْنُ شِهَابٍ عَنْ أَنَسِ بْنِ مَالِكٍ أَنَّ النَّبِيَّ ﷺ دَخَلَ مَكَّةَ عَامَ الْفَتْحِ وَعَلَى رَأْسِهِ مِغْفَرٌ فَلَمَّا نَزَعَهُ جَاءَهُ رَجُلٌ فَقَالَ ابْنُ خَطَلٍ مُتَعَلِّقٌ بِأَسْتَارِ الْكَعْبَةِ . فَقَالَ " اقْتُلُوهُ " . فَقَالَ مَالِكٌ نَعَمْ .

Jabir b. 'Abdullah al-Ansari (Allah be pleased with them) reported that Messenger of Allah ﷺ entered Mecca and Qutaiba (another narrator) stated that he entered Mecca in the Year of Victory, wearing a black turban, but not wearing the Ihram.

حَدَّثَنَا يَحْيَى بْنُ يَحْيَى التَّمِيمِيُّ، وَقُتَيْبَةُ بْنُ سَعِيدٍ الثَّقَفِيُّ، قَالَ يَحْيَى أَخْبَرَنَا وَقَالَ، قُتَيْبَةُ حَدَّثَنَا مُعَاوِيَةُ بْنُ عَمَّارٍ الدُّهْنِيُّ، عَنْ أَبِي الزُّبَيْرِ، عَنْ جَابِرِ بْنِ عَبْدِ اللَّهِ الأَنْصَارِيِّ، أَنَّ رَسُولَ اللَّهِ ﷺ دَخَلَ مَكَّةَ - وَقَالَ قُتَيْبَةُ دَخَلَ يَوْمَ فَتْحِ مَكَّةَ - وَعَلَيْهِ عِمَامَةٌ سَوْدَاءُ بِغَيْرِ إِحْرَامٍ . وَفِي رِوَايَةِ قُتَيْبَةَ قَالَ حَدَّثَنَا أَبُو الزُّبَيْرِ عَنْ جَابِرٍ .

Jabir b. Abdullah reported that Allah's Apostle ﷺ entered on the day of Victory of Mecca wearing a black turban on his head. and she said: In case Allah cures me I will certainly go and observe prayer in Bait al-Maqdis. She recovered and so she made preparations to go out (to that place). She came to Maimuna. the wife of Allah's Apostle ﷺ. and after greeting her she informed her about it, whereupon she said: Stay here. and eat the provision (which you had made) and observe prayer In the mosque of the Messenger ﷺ. for I heard Messenger of Allah ﷺ say: Prayer in it is better than a thousand prayers observed in other mosques except the mosque of the Ka'ba.

حَدَّثَنَا عَلِيُّ بْنُ حَكِيمٍ الأَوْدِيُّ، أَخْبَرَنَا شَرِيكٌ، عَنْ عَمَّارٍ الدُّهْنِيِّ، عَنْ أَبِي الزُّبَيْرِ، عَنْ جَابِرِ بْنِ عَبْدِ اللَّهِ، أَنَّ النَّبِيَّ ﷺ دَخَلَ يَوْمَ فَتْحِ مَكَّةَ وَعَلَيْهِ عِمَامَةٌ سَوْدَاءُ .

Amr b. Huraith reported on the authority of his father that Messenger of Allah ﷺ addressed the people (on the day of the Victory of Mecca) with a black turban on his head.

حَدَّثَنَا يَحْيَى بْنُ يَحْيَى، وَإِسْحَاقُ بْنُ إِبْرَاهِيمَ، قَالاَ أَخْبَرَنَا وَكِيعٌ، عَنْ مُسَاوِرٍ، الْوَرَّاقِ عَنْ جَعْفَرِ بْنِ عَمْرِو بْنِ حُرَيْثٍ، عَنْ أَبِيهِ، أَنَّ رَسُولَ اللَّهِ ﷺ خَطَبَ النَّاسَ وَعَلَيْهِ عِمَامَةٌ سَوْدَاءُ .