Imam Ibn Rajab Al-Hanbali (d. 795 AH), may Allah be pleased with him, declared about the first month, Muharram:
There is the hadith of Abu Hurairah, may Allah be pleased with him, that establishes that it is the best prayer after the compulsory. Is qiyam ul-lail superior to the sunan ratibah? There is some dispute in this but the discussion was already referenced previously.
Ibn Mas`ud, may Allah be pleased with him, said, “The favour of the prayer in the night made over the prayer in the day is like the favour of the sadaqah done in secret over the sadaqah done in the open.” There is also an attributable hadith collected by At-Tabarani that references this point and it is preserved.
`Amr ibn Al-`As said, “A rak`ah in the night prayers is better than ten raka`at made in the day.” This was collected by Ibn Abid-Dunya.
The prayer made at night is only favoured over the one in the day as it is more in secret and in that way closer to sincerity as others are not watching. The first three generations used to strive in concealing their tahajjud.
Al-Hasan Al-Basri said, “There was a man who had visitors at his house and he would stand in the night praying while none of his visitors knew about the matter.”
The first three generations used to strive in making supplication but others could not hear their voice when they made the supplications. The man would sleep with his wife on a pillow and he would weep the whole night long while she had no knowledge of the affair.
Muhammad ibn Wasi` used to pray on the way to the Hajj the night long and he would order his servant to raise his voice to distract the people from knowing about him. One of the early generations stood in the middle of the night and it was not known about by the people.
When the time came for the Fajr, he raised his voice with the Qur’an to make someone think that he had just risen at that time. And night prayer is preferred over the day prayer as the prayer at night is more difficult on the soul to carry out.
The night is a time of sleep and rest from exertion carried out in the daytime. Thus the one who rises and leaves his bed and sleep in order to carry out worship causes the self to incline towards a very serious form of personal struggle.
One of the early generations said that the best of deeds is what is disliked by the human self. And it is also preferred as recitation in the night prayer is nearer to reflection as one is not distracted in the night and the heart is attentive. The heart and the tongue then come together for comprehension as the Exalted One said,
And the standing in the night as the most difficult and also the most rewarding and rectifies.
And it is due to this that he commanded with proper and slow recitation of the Qur’an in the qiyam ul-lail . The night prayer also forbids one from sin just as will be coming in a hadith extracted and collected by At-Tirmidhi.
In the Musnad in a hadith cited by Abu Hurairah, may Allah be pleased with him, the Prophet, peace and blessings of Allah be upon him, was told that a man prayed in the night and then in the morning stole, so how could that be?
The Prophet, peace and blessings of Allah be upon him, said, “The night prayer will surely take him away from that which you are talking about of his bad deed.” So the night of tahajjud in the night is the noblest of extended times in prayer and the slave is nearer to his Lord at that time.
This is also the very time in which the doors of the sky are opened, supplications are answered and the needs of the beseechers are met. Allah, Exalted be He, has praised those who wake up in the night to remember Him, supplicate to Him, ask forgiveness from Him, have intimate contact with Him.
Source: Lata’if ul-Ma`arif Fima Li-Mawasim il-`Ami Min Al-Waza’if, pp. 43-45