Imam Jafar Sadiq (a.s.) informed regarding the verse: “They shall not control intercession, save he who has made a covenant with the All-Beneficent God.” (Surah Maryam (19):87)

Their intercession is not accepted, intercession will not be done for them and they will not intercede except for those who have made a covenant with Allah and except for those who are permitted from the aspect of the mastership (Wilayat) of Ameerul Momineen Ali (a.s.) and the Imams after him as the covenant with Allah is this only.
Tafseer al-Qummi under Surah Maryam: 87