They quoted as evidence for that the hadeeth of Ibn Mas’ood (may Allaah be pleased with him), according to which the Prophet (peace and blessings of Allaah be upon him) taught the Sahaabah the Tashahhud, then he said at the end of it: “Then let him choose whatever supplications he wishes.” Narrated by al-Bukhaari (5876) and Muslim (402).
Ibn Abi Shaybah narrated in al-Musannaf (1/331) that al-Hasan and al-Sha’bi said:
Ask during your prayer for whatever you want. End quote.
It says in al-Mudawwanah (1/192):
Maalik said: There is nothing wrong with a man praying for all his needs in the prescribed prayers, for his needs in this world and in the Hereafter, when standing, sitting and prostrating. He said: Maalik told me that ‘Urwah ibn al-Zubayr said: I heard from him that he said: I ask Allaah for all my needs when praying, even for salt. End quote.
The Maalikis and Shaafa’is are of the view that it is Sunnah to say du’aa’ after the Tashahhud and before saying the salaam, asking for the best of religious and worldly things, but it is not permissible to say du’aa’ asking for anything haraam or impossible or conditional. If a person says du’aa’ asking for any such thing then his prayer is invalidated, and it is best to say du’aa’ using words that are mentioned in reports. End quote.
Al-Nawawi (may Allaah have mercy on him) said in al-Majmoo’ (3/454):
Our view is that it is permissible to say du’aa’ in prayer for that which it is permissible to ask for outside of prayer, of religious and worldly matters. So one may say: O Allaah, bless me with good (halaal) earnings, and a child, and a house, and a beautiful wife, describing her, or: O Allaah, set So and so free from prison, and destroy So and so, and the like, and his prayer is not invalidated by any of that in our view.
Our companions quoted as evidence the words of the Prophet (peace and blessings of Allaah be upon him), “As for prostration, strive hard in du’aa’ therein.”
The command to say du’aa’ is general in meaning, and was not restricted, so it applies to everything that is called du’aa’.
And because the Prophet (peace and blessings of Allaah be upon him) said du’aa’ at various points (in the prayer), which indicates that there is no restrictions on that.
In al-Saheehayn, in the hadeeth of Ibn Mas’ood (may Allaah be pleased with him), it is narrated that the Prophet (peace and blessings of Allaah be upon him) said at the end of the tashahhud: “Then let him choose whatever supplications he likes or wishes”.
According to a report narrated by Abu Hurayrah: “Then let him pray for himself as he sees fit.” Al-Nasaa’i said: Its isnaad is saheeh.
Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) said in al-Sharh al-Mumti’ (3/283):
There is nothing wrong with asking for things that have to do with worldly matters, because du’aa’ in itself is an act of worship, even if it is asking for worldly things, and man has nowhere to turn but to Allaah. The Messenger (peace and blessings of Allaah be upon him) said, “The closest that a slave is to his Lord is when he is prostrating” and he said, “As for prostration, say a great deal of du’aa’ in it, because it is more likely that you will receive a response.” And according to the hadeeth of Ibn Mas’ood, when he spoke of the Tashahhud, he said: “Then let him choose whatever supplications he wishes.” A person is never turning to Allaah as fully as he is in prayer, so how can we say Do not ask Allaah, when you are praying, for anything that you need of worldly things! This is very unlikely.