(Al-ṣuḥb and mutual obligations within the tribe)

Answer – and Allah is the One who grants success – is that al-ṣuḥb, and the obligations and covenants among the members of a tribe, are something good which must be fulfilled, except for whatever involves sin or aggression; such must not be fulfilled, for the covenant with Allah has a greater right to be fulfilled.
And Allah, Exalted is He, has made it obligatory upon those who are legally accountable to fulfill covenants and contracts. He, Most High, said: “And fulfill [every] commitment. Indeed, the commitment is ever [that about which one will be] questioned.” [al-Isrā’:34] and: “O you who have believed, fulfill [all] contracts.” [al-Mā’idah:1] and: “But yes, whoever fulfills his commitment and fears Allah – then indeed, Allah loves those who fear Him.” [Āl ʿImrān:76]. The verses in this regard are many. And in the well-known hadith, breaking one’s promise is among the characteristics of the hypocrites. And Allah, Exalted is He, praised Ismaʿil (Peace be Upon Him), saying: “And mention in the Book, Ishmael. Indeed, he was true to his promise, and he was a messenger and a prophet.” [Maryam:54].

Source: Min Thimār al-ʿIlm wa al-Ḥikmah vol.2