Is there expiation for breaking an oath not to return to a sin that was committed unintentionally? And what is the ruling on posting pictures of a deceased person on Facebook?

Whoever swears to abandon a sin and then breaks his oath, an expiation for the oath becomes obligatory upon him. He has the choice between feeding ten poor persons, or clothing them, or freeing a slave. If he cannot find any of these, then he must fast for three days, based on the verse: "Its expiation is the feeding of ten poor persons from the average of that which you feed your [own] families, or clothing them, or the freeing of a slave. But whoever finds none - then a fast of three days."

Furthermore, one must hasten to sincere repentance from the sin. As for placing pictures of the deceased with the aim of stirring up grief, it is not permissible because it is akin to wailing (niyaḥa), which is forbidden. However, if it is for remembrance, supplication, and similar purposes that do not involve a Sharia prohibition, then there is no harm in it, as long as the pictures do not include a Sharia violation.