Is it permissible to continue breastfeeding after the specified two years, and if so, what is the maximum permissible duration thereafter?

Allah Almighty made the completion of breastfeeding two full years for those who wish to complete the breastfeeding, as He says: (And mothers shall breastfeed their children for two full years, for whoever wishes to complete the nursing) Al-Baqarah/233.

And there is no harm in continuing breastfeeding after two years if it is for the child's benefit, and it is permissible to exceed or fall short of the two years if it does not harm the infant and if both parents agree.