What are the rulings on breastfeeding, especially in the case of breastfeeding the husband's nephew, who is one month younger than one's own son, knowing that the son was breastfed by the husband's brother's wife, and in the presence of other children from both parties? What is the type and quantity of breastfeeding that establishes prohibition, and what are the rulings that apply to the remaining siblings?

For prohibitory suckling (rada'ah muharramah) to be established, five fulfilling sucklings (rada'at mushbi'at) are required within the first two years of life (hawlain). So, whoever suckles from a woman five times within the first two years becomes her son and her husband's son through suckling, and a brother to everyone who suckled from the same woman. This is based on the Prophet's (peace be upon him) saying: "There is no suckling except within the first two years," and "What is forbidden by lineage is also forbidden by suckling." A suckling (rad'ah) is defined as the baby taking the breast and sucking milk, then letting go, and minor interruptions do not invalidate it.