The Messenger of Allah (ﷺ) as saying: There is no alliance in Islam, and Islam strengthened the alliance made during pre-Islamic days.
Sunan Abi Dawud Book 19, Hadith 41
← Previous Hadith Referring to the verse: "Those who believed and adopted exile... As to those who believed but came not into exile": A bedouin (who did not migrate to Medina) did not inherit from an emigrant, and an emigrant did no inherit from him. It was abrogated by the verse: "But kindred by blood have prior rights against each other."

Sunan Abi Dawud Book 19, Hadith 40 Next Hadith → The Messenger of Allah (ﷺ) established an alliance (of brotherhood) between the Emigrants and the Helpers in our house. He was asked: Did not the Messenger of Allah (ﷺ) say: There is no alliance in Islam ? He replied: The Messenger of Allah (ﷺ) established an alliance between the Emigrants and the Helpers in our house. This he said twice or thrice.

Sunan Abi Dawud Book 19, Hadith 42