Is it sufficient to free a slave born of zina?

Ibrahim and Hazrat Sha'bi state that where it is obligatory to free a slave, it is not permissible to offer a child born out of wedlock.

Hazrat Usman bin Al-Aswad says that a person from my family passed away and he had made a will to free a slave. I found a slave whose parents had married without the permission of the guardian. I asked Hazrat Ata about this, and he said, "I dislike this."

Hazrat Fulan bin Amr says that I asked Hazrat Abu Ja'far about freeing a child of adultery as expiation for an oath. He replied, "It will suffice."

Yunus says that a slave born of adultery will suffice, and a slave of sound lineage does not grant any superiority to the emancipator except for piety.

Hazrat Tawus says that freeing a child born out of wedlock will suffice in the emancipation of a slave.

Ibrahim says that in the obligatory land grant, giving a child of adultery is not sufficient.

Hazrat Saeed bin Abu Saeed narrates that a woman came to Hazrat Abu Hurairah (may Allah be pleased with him) and asked: "I have a slave woman’s son who is not of sound lineage, and it is obligatory upon me to free a slave. Will freeing him suffice?" He replied: "Yes."