What is the solution to the problem of having an infant during ṭawāf and saʿy in 'umrah when there is no one to care for him, and is it permissible to breastfeed him if he gets hungry during ṭawāf and then complete the ṭawāf?

It is permissible to carry an infant during 'Umrah. There is no harm in sitting and resting during Tawaf or Sa'i to nurse the child or for any other reason, and then completing Tawaf and Sa'i. It has been authentically reported from Ibn 'Umar, 'Ata', and Al-Hasan that it is permissible to rest during Tawaf and Sa'i.