Specifying a number of times to recite dhikr or du’aa’ that is not narrated in sharee’ah
There is no sound (saheeh) basis for reciting these adhkaar the number of times mentioned in the question. These numbers are usually stated by some of the innovators, most of whom are Sufis, who describe adhkaar and the number of times they are to be repeated, making that up themselves; they say whoever recites such and such will get such and such benefits and protection, and whoever recites such and such a wird will get such and such a reward.
Of course, these are matters which can only be known through wahy (revelation). So the basic principle in this case is that dhikr and du’aa’s are of two types:
1 – Adhkaar which were narrated in the Qur’aan and Sunnah, to be recited at a certain time, in a certain place or in certain circumstances. This type should be recited as prescribed, at the appropriate time, or in the appropriate circumstances or place, with the correct words or posture, without adding anything or taking anything away.
2 – All dhikr or du’aa’ in general that is not connected to certain times or places. These fall into two categories:
(i) Those which were narrated from the Prophet (peace and blessings of Allaah be upon him), so they should be recited in the wording that he used. They should not be connected to any particular time or place, and they should not be connected to a specific number of times to be recited.
(ii) Those which were not narrated from the Prophet (peace and blessings of Allaah be upon him), rather the person makes them up himself, or they were narrated from the salaf. It is permissible to say such words so long as five conditions are met:
1- He should choose the best and clearest words, for he is conversing with his Lord and God.
2- The words should be of an appropriate style.
3- The du’aa’ should be free of anything that is forbidden in Islam, e.g. it should not involve any element of seeking help from anything other than Allaah, and so on.
4- It should be of the general kind of dhikr and du’aa’, not connected to a particular time, place or circumstances.
5- It should not be taken as a regular practice.
Adapted from Tasheeh al-Du’aa’ by Shaykh Bakr Abu Zayd (p. 42)
Based on the above, the words mentioned in the question are phrases that are narrated in the Qur’aan and Sunnah, but saying that they must be repeated this number of times is an innovated matter which should not be followed. Rather we should mention them during our du’aa’s and address Allaah by all His beautiful names, without singling out some names or stating that they should be recited a certain number of times or at certain times, making that up ourselves. We should adhere to what was narrated in sharee’ah concerning certain times, places or situations connected to a particular du’aa’; if no such details were narrated in sharee’ah then we should not make them up ourselves because that is encroaching upon the rights of Prophethood.
And Allaah knows best.