Is the one who gives up on marriage because he can`t afford it considered sinful?
Marriage is desirable, but one who can`t afford it isn`t considered sinful. However, he should supplicate to Allah, and seek His forgiveness.
What is the ruling if a postpartum woman becomes pure before forty days; are acts of worship obligatory upon her, and is she permissible for her husband?
If the postpartum woman becomes definitely pure before forty days, she must perform the ritual bath and perform acts of worship as a pure woman does. What was prohibited for her also becomes permissible, so she becomes permissible for her husband after her bath. The minimum duration for postpartum bleeding is a moment (an instant), and its usual maximum is forty days. Reaching forty days is not a condition; rather, it is sufficient for the blood to stop or to see the white discharge (qassa bayda'). And Allah the Almighty knows best.
Does the clipping of nails nullify ablution?
No, it does not, and it is preferable to wash the hands afterwards.
Is it permissible to offer an Udhiyah on behalf of the deceased?
In the Name of Allah, and may peace and blessings be upon our Master, the Messenger of Allah.
Offering an Udhiyah (sacrificial animal) on behalf of a deceased person is permissible. This is the official position of the Hanbali school (as stated in Kashshaf al-Qina’ by al-Bahuti,Vol.6/P.428) and was also upheld by the prominent Shafi'i scholar Al-’Abbadi (mentioned in Bidayat al-Muhtaj by Ibn Qadi Shuhbah,Vol. 4/P.358). It has likewise been narrated as a valid view among some Maliki and Hanafi scholars.
In fact, Imam Abu Dawud dedicated an entire chapter in his Sunan collection entitled, "Chapter on Sacrificing on Behalf of the Deceased." In it, he recorded a narration from Hanash, who said: "I saw 'Ali sacrificing two rams, so I asked him, 'What is this?' He replied, 'The Messenger of Allah (peace and blessings be upon him) commanded me to offer a sacrifice on his behalf, so I am sacrificing on his behalf.'"
Imam Abu Dawud also narrated from Jabir (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "O Allah, this is from You, for You, and on behalf of Muhammad and his Ummah (community). In the Name of Allah, and Allah is the Greatest," and he then slaughtered the animal.
The textual evidence here lies in the fact that our Master, the Prophet (peace and blessings be upon him), offered a sacrifice on behalf of his entire community—and it is well-established that his community includes those who have already passed away.
Furthermore, there is an abundance of sacred texts demonstrating that the rewards of righteous deeds reach the deceased. For instance, it is permissible to fast on behalf of a deceased person who passed away with missed obligatory fasts, and it is equally permissible to perform Hajj on their behalf, both of which are firmly established in authentic Hadiths. Therefore, if the reward of fasting (which is a purely physical act of worship) and Hajj (which is a joint physical and financial act of worship) can reach the deceased, then the reward of an Udhiyah reaches them with greater reason (by way of A Fortiori argument). This is because it is a purely financial act of worship, falling under the general category of charity (Sadaqah).
Additionally, scholars have reached a consensus (Ijma') that the rewards of charity reach the deceased, and since the Udhiyah is inherently an act of charity, it falls under the same ruling. Consequently, based on all the aforementioned evidence, we hold the view that offering a sacrifice on behalf of the deceased is entirely permissible. And Allah the Almighty Knows Best.