What is the ruling on the prayer of one who said "Subḥāna Rabbiya al-ʿAẓīm" in prostration (*sujūd*) and forgot to correct it?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah.
Saying “Subḥāna Rabbiya al-ʿAẓīm” in bowing (rukūʿ) and “Subḥāna Rabbiya al-Aʿlā” in prostration (sujūd) is one of the hayʾāt (non-essential sunnahs) of the prayer. Whoever omits it, whether deliberately or by forgetfulness, or replaces it with another remembrance (dhikr), his prayer is valid and he does not perform sujūd al-sahw. Shaykh al-Islām Imam al-Nawawī (may Allah have mercy on him) said: “Our school holds that one does not prostrate for omitting the audible or silent recitation, the tasbīḥ, and the rest of the hayʾāt.” [al-Majmūʿ, Vol.4/p.127]
If he performs sujūd al-sahw for something that does not call for it, his prayer is invalidated, because he introduced a prostration of forgetfulness without a cause, and he must repeat the prayer. The exception is one who did so out of forgetfulness or ignorance, whether because he recently entered Islam or because he lives far from scholars; he is excused and his prayer is not invalidated.
It is stated in Mughni al-Muḥtāj (Vol.1/p.417): “It is stated in al-Anwār: If he does something that does not call for sujūd al-sahw, thinking that it does, and then prostrates, his prayer is not invalidated if he is ignorant because he recently entered Islam or because he is far from scholars.”
Since this issue is hidden from the laity, as it is among the subtleties of knowledge, and the laity are excused for ignorance of whatever is of such a nature, and their act of obedience is not invalidated because of it, it may be said that the prayer of one who has not acquired knowledge of the issue is not invalidated. As for after knowing it, the prayer is invalidated.
Whoever realizes while still in the prayer that his prostration was out of place, it is sunnah for him to perform sujūd al-sahw. And Allah Almighty knows best.
Is Zakah (obligatory charity) due on land intended for selling?
Yes, lands intended for trade are valued, and Zakah is paid according to their estimated value after a lunar year had lapsed, but if the owner didn`t pay the due Zakah, then he should do so after selling them.
What is the ruling on performing the standing (qiyām) and bowing (rukū‘) portions of the prayer normally, while performing the prostration (sujūd) seated due to knee pain?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah ﷺ.
If performing sujūd (prostration) in prayer causes the worshipper pain in the knees, then it is permissible for him to perform it through gesture (īmā') while seated, since Allah, Glorified and Exalted is He, has lifted hardship from His servants. On the authority of ‘Imrān ibn Ḥuṣayn (raḍiyallāhu ‘anh), he said: "I suffered from hemorrhoids, so I asked the Prophet ﷺ about [how to perform] the prayer, and he said: 'Pray standing; if you are unable, then sitting; and if you are unable, then on your side.'" [Ṣaḥīḥ al-Bukhārī]
If the valid excuse later subsides, the worshipper is then obligated to perform the prayer with all its pillars and conditions fully observed — including standing, rukū‘ (bowing), and sujūd (prostration). And Allah, the Exalted, knows best.
A woman became pure [from menstruation] before Fajr, but did not perform ghusl until after sunrise — what is the ruling on her fast?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah ﷺ.
Her fast is valid, since ghusl (ritual bathing) is not a condition for the validity of the fast, but rather for the validity of the prayer. However, she is sinful for delaying the Fajr prayer beyond its designated time without a valid excuse.
It is known that the time for Fajr prayer ends at sunrise. Nevertheless, she must still perform ghusl, and make up the Fajr prayer. And Allah, the Exalted, knows best.