Sheikh Bandar b. Nâyif al-`Abdalî, professor at al-Qasîm University
Your question is in two parts. The fist part deals with whether it is necessary to seek Allah’s salutations upon the Prophet (peace be upon him) in our personal supplications in order to have those supplications accepted. The second part of your question deals with doing so in our formal prayers when we are supplication in prostration.
Regarding the first part of your question, there are a number of hadîth narrations that give the meaning: “Any supplication where Allah’s salutationss are not invoked upon the Prophet is barred from acceptance.”
However, all of these hadîth suffer from serious defects and they are not authentically established.
For instance, there is a narration that reads: “There is a barrier between every supplication and Heaven until, when Allah’s salutations are sought for Muhammad (peace be upon him), the barrier is broken and the supplication is answered.”
This narration suffers from three defects:
1. One of its narrators is al-Hârith al-A`war, who has been accused of lying. He claims to relate this hadîth from Alî b. Abû Tâlib.
2. Abû Ishâq al-Subay`î is the narrator who relates this hadîth from Hârith. However, it is known that Abû Ishâq al-Subay`î only heard four hadîth from Hârith, and this is not one of them. This has been confirmed by Shu`bah.
3. There is another narration of this statement by way of Thâbit through Abû Ishâq which narrates this as the statement of Alî and not as the words of the Prophet (peace be upon him).
All the other narrations of this hadîth are similarly defective. [refer to: Jalâ’ al-Ifhâm by Ibn al-Qayyim]
The second part of your question asks about seeking Allah’s blessings upon the Prophet (peace be upon him) in our formal prayers when we are supplication in prostration. The answer is that we should not do so when we are prostrating. There is no evidence to support this practice.
The hadîth mentioned above are unauthentic. Moreover, even if those hadîth were authentic, they are talking about the supplications that we make outside of our formal prayers.
As for our formal prayers, how we offer them is strictly determined by the sacred texts. The supplications we offer during our formal prayers are part of those prayers, and there is no evidence that the Prophet (peace be upon him) ever invoked Allah’s salutations upon himself when he prostrated in prayer.
And Allah knows best.
Source: Islam Today