The Companions of the Tree (i e. those who swore fealty under the tree) were one thousand and three hundred, and the people of Aslam tribe were one-eighth of the Muhajirs.
كَانَ أَصْحَابُ الشَّجَرَةِ أَلْفًا وَثَلاَثَمِائَةٍ وَكَانَتْ أَسْلَمُ ثُمُنَ الْمُهَاجِرِينَ
[Machine] "Abdullah ibn Abi Aufa was one of the companions of the Prophet ﷺ and he was one of the 1,400 individuals from the Ansar who embraced Islam on that day which was known as "The Day of the Migrants.""
عَنْ عَبْدِ اللَّهِ بْنِ أَبِي أَوْفَى «وَكَانَ مِنْ أَصْحَابِ الشَّجَرَةِ أَلْفًا وَأَرْبَعُمِائَةٍ وَكَانَتْ أَسْلَمُ ثُمُنَ الْمُهَاجِرِينَ يَوْمَئِذٍ»
[Machine] I heard Abdullah bin Abi Awfa saying, "There were one thousand and three hundred of us on the day of the Treaty of Hudaybiyyah, and at that time, the number of Muslims was eight hundred. May Allah have mercy on them."
سَمِعْتُ عَبْدَ اللَّهِ بْنَ أَبِي أَوْفَى يَقُولُ «كُنَّا يَوْمَ الشَّجَرَةِ أَلْفًا وَثَلَاثَ مِائَةٍ وَكَانَتْ أَسْلَمُ يَوْمَئِذٍ ثُمْنَ الْمُهَاجِرِينَ رَحِمَهُمُ اللَّهُ»
"عَنْ عَبْدِ اللهِ بْنِ أَبى أَوْفَى قَالَ: كنَّا يَوْمَ الشَّجَرَةِ أَلفًا وَأرْبَعَمايةٍ، أَوْ أَلفًا وَثَلاثمائة وَكَانَتْ أَسْلَمُ يَوْمَئِذٍ ثُمْنَ المُهَاجِرينَ".