What is the religious ruling on my saying, while angry, "He was right who used to bury girls alive," and what should I do to atone for this sin?

God has forbidden the burying alive of daughters, and whoever commits this act is guilty of a forbidden deed. Therefore, whoever regrets what has happened must increase their seeking of forgiveness, repentance, and righteous deeds. Allah Almighty says: "But whoever repents after his wrongdoing and makes amends, indeed, Allah will turn to him in forgiveness. Indeed, Allah is Forgiving and Merciful." It is also necessary to continue advising the children gently, to let them hear the revelation, to find good company for them, to seek Muslim husbands for the daughters, and to strive to protect one's family from the Fire.