Is it permissible to delay the Dhuhr prayer by an hour from its due time because the shop owner is busy selling necessities to students, and is it permissible to pray at home under the same circumstance?

Congregational prayer is obligatory for an able-bodied man, and it is not permissible for him to miss it except for a legitimate excuse. Waiting for customers is not an excuse. It is permissible for him to wait for students to pray in congregation with them if he finds a congregation after they leave, because the virtue of congregational prayer is attained through congregational prayer outside the mosque, and the time for Dhuhr prayer is extensive. Going to the mosque and performing the prayer there is better.