What are the ties of kinship that are obligatory to maintain, what is the periodic frequency for maintaining kinship ties, and is there sin upon one who finds difficulty in maintaining ties with forty relatives and their children and grandchildren?

Scholars have differed in defining the kinship ties that are obligatory to maintain. The most preponderant view is that they are of two types: kinship ties that are obligatory to maintain and forbidden to sever, which include all unmarriageable kin (like paternal aunts, maternal aunts, paternal uncles, and maternal uncles); and kinship ties that are disliked to sever and recommended to maintain, which include all marriageable kin (like paternal cousins and maternal cousins). Maintaining these ties is achieved through visiting, showing kindness, fulfilling needs, greeting, writing, and calling. There is no specific time limit for this; rather, it depends on custom and the closeness or distance of the kin.