The students in some schools stand up, clasp their hands and repeat the words “O our Father we thank you for the night…” What is the ruling on that?

Firstly: 

The Messenger of Allah (blessings and peace of Allah be upon him,) who is the most truthful one, told us that this ummah would follow the ways of the Jews and Christians. It was narrated from Abu Sa ‘eed (may Allah be pleased with him) that the Prophet (blessings and peace of Allah be upon him) said: “You will certainly follow the ways of those who came before you hand span by hand span, cubit by cubit, to the extent that if they entered the hole of a lizard, you will enter it too.” We said: “O Messenger of Allah, (do you mean) the Jews and the Christians?” He said: “Who else?” Narrated by al-Bukhaari, 1397; Muslim, 4822. 

This hadeeth indicates that it is haraam to imitate the Jews and the Christians, and that those who follow them and tread the same path as them are criticized. Islam has reinforced this prohibition, by describing those who imitate the kuffaar as being of them.  

It was narrated that ‘Abdullah ibn ‘Umar (may Allah be pleased with him) said: The Prophet (peace and blessings of Allah be upon him) said: “Whoever imitates a people is one of them.” Narrated by Abu Dawood, 3512; classed as saheeh by al-Albaani in Irwa’ al-Ghaleel, 2691.  

Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said: 

This at the very least indicates that it is haraam to imitate them, although the apparent meaning is that the one who imitates them is a kaafir. 

Iqtida’ al-Siraat al-Mustaqeem, 237. 

The phrase asked about here (“O our Father we thank you for the night…”) Is most likely to be a Jewish or Christian prayer, because they are the ones who describe God, may He be glorified, as their Father, exalted be Allah above what they say. Indeed Allah, may He be glorified, and His Angels and His Messengers have nothing to do with them or their disbelief. This is confirmed in the Qur’an where Allah, may He be exalted, says (interpretation of the meaning):

“And (both) the Jews and the Christians say: ‘We are the children of Allah and His loved ones.’ Say: ‘Why then does He punish you for your sins?’ Nay, you are but human beings, of those He has created, He forgives whom He wills and He punishes whom He wills. And to Allah belongs the dominion of the heavens and the earth and all that is between them, and to Him is the return (of all)”

[al-Maa’idah 5:18]. 

In fatwa no. 160791 we stated that it is not permissible to address Allah, may He be glorified and exalted, by saying “O my Father” or “O our Father”; these are the words of the people of the two previous Books, the Jews and Christians. 

Based on that, it is not permissible to use this phrase in supplication (du‘aa’). 

Secondly: 

With regard to the question about using this phrase in the prayer “O Allah, we thank you for the night…”, this, by Allah, is something strange and is indicative of how far this ummah has sunk into humiliation, feelings of inferiority and backwardness, and defeatist thinking. Hence it hastens to imitate the disbelievers even in their prayers and religious rituals. It is absolutely astounding that anyone would forsake the Qur’anic du‘aas that are from the words of the Lord of the Worlds, may He be glorified and exalted, and would forsake the Prophet’s du‘aa’s, and the adhkaar of the morning and evening which are the words of the best of mankind, then hasten to use the prayers of the disbelievers after introducing some modifications and improvements to them. 

One may say that there is nothing wrong or objectionable in saying “O Allah, we thank You for the night” in and of itself, for morning and evening (or day and night) are among the blessings that Allah has bestowed upon His slaves, for which they should give thanks, as Allah, may He be exalted, says (interpretation of the meaning):

“Say (O Muhammad (blessings and peace of Allah be upon him)): ‘Tell me! If Allah made day continuous for you till the Day of Resurrection, who is an ilah (a god) besides Allah who could bring you night wherein you rest? Will you not then see?’

It is out of His Mercy that He has put for you night and day, that you may rest therein (i.e. during the night) and that you may seek of His Bounty (i.e. during the day), and in order that you may be grateful”

[al-Qasas 28:72-73].

But if the one who says that is bearing in mind what the disbelievers say and paying attention to their wording in their supplication, then this undoubtedly comes under the heading of imitation of the disbelievers which is prohibited, especially when it has to do with a matter of worship and remembering Allah, may He be exalted. 

Therefore it is haraam to stick to such wording and to choose it deliberately, in this regard. 

Moreover, the matter becomes even more emphatically prohibited, and the one who does it definitely falls into the category of imitation of the disbelievers which is prohibited, if that is accompanied by clasping the hands in the manner mentioned, as the disbelievers, Hindus and others, do in their prayers and worship. 

For more information, please see the answer to question no. 21341 

And Allah knows best.