Obligation of wearing Khimar during Salah

Q: I came across a question in a book entitled "Subul Al-Salam Sharh Bulugh Al-Maram" by Al-San`any, in the Chapter on conditions of Salah (Prayer). The author explained the Hadith reported by `Aishah (may Allah be pleased with her) that the Prophet (peace be upon him) said: Allah does not accept the prayer of a menstruating woman (i.e., an adult woman) unless (she covers her head) with a head-cover. The author, Al-San`any, (may Allah be merciful to him) said: Allah's acceptance of worship may mean the person's worthiness of reward. Hence the non-acceptance of worship means unworthiness of reward not the invalidity of the worship itself as reportedly mentioned in the Hadith: Allah does not accept the prayer of a runaway slave or of one in whose abdomen there is alcohol. Here lies the subject of my questions:The first question: Is this Hadith authentic?The second question: Is the Salah of a runaway slave and the person who drinks alcohol not accepted by Allah, that is, if they pray, Allah will not reward them for this Prayer? Is it just their Salah that Allah will not accept, or does this apply to other acts of worship they offer such as Zakah, Sawm, and Hajj?The third question: Can we compare a fornicator to them (Part No. 5; Page No. 144) and say that the fornicator's Salah is sufficient for him because he is legally competent to offer Salah, yet Allah will not reward him even if he offers Salah his whole life?Finally, can we compare all the punishable sins such as theft and so on, to the case in this question?We appreciate your advice, may Allah reward you with the best for what you do for Islam and Muslims.

A: The Hadith is authentic; it means that when a young girl reaches the age of puberty, she has to cover her hair and all her body except her face, unless there are strange men around her while offering Salah (i.e. In that case she has to also cover her face); because a woman's body except for her face has to be covered in Salah. One of the signs that indicate that a young girl has reached the age of puberty is menstruation. In this case, the Hadith is evidence for the invalidity of a woman's Salah without covering her `Awrah (parts of the body that must be covered in public). It does not mean her unworthiness of Allah's Reward for Salah, as mentioned by Al-San`any (may Allah be merciful to him); because Allah's non-acceptance of an act of worship basically means the invalidity of this worship unless there is proof that indicates the unworthiness of the reward, as in the Hadith about the Salah of a runaway slave and the person who drinks alcohol, and as in the other Hadith related by Muslim in his (Sahih Muslim) from the Prophet (peace be upon him) where he said: He who visits a diviner and asks him about anything, his prayers extending to forty nights will not be accepted. According to all religious scholars, acceptance here means the unworthiness of reward for Salah, not the invalidity of Salah. Therefore a runaway slave and the person who drinks alcohol or visits a diviner (Part No. 5; Page No. 145) and asks him about anything do not have to repeat their Salah. The opposite case is in the Saying of the Prophet (peace be upon him): Neither is a prayer accepted without purification nor is charity accepted out of ill-gotten (wealth). (Related by Muslim in his book [Sahih Muslim] from the Hadith reported by Ibn `Umar [may Allah be pleased with him and his father]) This is in addition to the Saying of the Prophet (peace be upon him): The Prayer of none among you will be accepted if he is in a state of impurity until he performs ablution. (Agreed upon by Al-Bukhari and Muslim from the Hadith reported by Abu Hurayrah [may Allah be pleased with him])May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.